{"Bibliographic":{"Title":"Standard formats for weather data exchange among automated weather information systems","Authors":"","Publication date":"1986","Publisher":""},"Administrative":{"Date created":"08-17-2023","Language":"English","Rights":"CC 0","Size":"0000163071"},"Pages":["86\nDEPARTMENT OF COMMERCE / National Oceanic and Atmospheric Administration\nFEDERAL COORDINATOR FOR\nOF\nMETEOROLOGICAL SERVICES\nAND SUPPORTING RESEARCH\nSTATES\nOF\nStandard Formats for\nWeather Data Exchange\nAmong Automated\nWeather Information\nSystems\nFCM-S2-1986\nWashington, D.C.\nDecember 1986","FEDERAL COMMITTEE FOR\nMETEOROLOGICAL SERVICES AND SUPPORTING RESEARCH (FCMSSR)\nFEDERAL COORDINATOR FOR\nMETEOROLOGICAL SERVICES AND SUPPORTING RESEARCH\nINTERDEPARTMENTAL COMMITTEE FOR\nMETEOROLOGICAL SERVICES AND SUPPORTING RESEARCH (ICMSSR)\nWorking Group for\nWorking Group for\nAutomated Weather\nOperational Processing\nInformation Systems\nCenters\nWorking Group\nfor Meteorological\nInformation Management\nSTANDING COMMITTEES\nAVIATION SERVICES\nSYSTEMS DEVELOPMENT\nWorking Group for Automated\nSurface Observations\nOPERATIONAL ENVIRONMENTAL\nWorking Group for Atmospheric\nSATELLITES\nTransport and Diffusion\nSPACE ENVIRONMENT\nWorking Group for Profiler\nFORECASTING\nSystems\nBASIC SERVICES\nWorking Groups\nMetric Implementation\nCooperative Backup Among Operational\nMonitoring the Stratosphere\nProcessing Centers\nRadar Meteorological Observations\nDissemination of NMC Products\nSatellite Telemetry Interagency\nDrifting Data Buoys\nSevere Local Storms Operations\nHurricane and Winter Storms Operations\nSurface Observations\nLightning Detection Systems\nUpper Air Observations\nMarine Environmental Predictions\nWorld Weather Program\nMeteorological Codes","QC\n874.3\n588\n-\n1986\nU. S. DEPARTMENT OF COMMERCE\nNATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION\nFederal Coordinator for\nMeteorological Services and Supporting Research\n11426 Rockville Pike, Suite 300\nRockville, Maryland 20852\nStandard Formats\nfor\nWeather Data Exchange\nAmong\nAutomated Weather Information Systems\nLIBRARY\nRecataloged\nJUL 2 2 1994\nWashington, D. C.\nDecember 1986\nN.O.A.A.\nFCM-S2-1986\nU.S. Dept. of Commerce\nSingle copies are available from:\nOffice of the Federal Coordinator for Meteorology at the above address.","#/10/30","FOREWORD\nComputers and microprocessors are being widely introduced into\nthe field level of operations of the several weather services and\namong their various users. These new systems provide a capability for\norganizing information in a variety of ways. The observance of\nstandards in the format of the weather information and protocols of\ncommunication is essential to the efficient exchange of information\namong the providers and efficient application by the users.\nThis document establishes standards of data formats for a number\nof product types, together with the elements of identification. The\nupdated material was prepared by the Task Group on Communication\nInterfaces and Data Exchanges established by the Working Group on\nAutomated Weather Information Systems as a function of the\nInterdepartmental Committee for Meteorological Services and Supporting\nResearch.\nThe rapidly evolving character of the technology of information\nhandling and the newness of these systems within the meteorological\ncommunity will undoubtedly present many opportunities and requests for\nmodification of these standards and the addition of others. It is\nanticipated that a standing group will be appointed to consider\nchanges and maintain the current set of operating standards.\nRobert L. Carnahan\nFederal Coordinator for\nMeteorological Services and\nSupporting Research\niii","","TABLE OF CONTENTS\nPage\n1.0\nINTRODUCTION\n1-1\n1.1 Purpose\n1-1\n1.2 Objective\n1-1\n1.3 Scope\n1-1\n1.4\nEssential Principals\n1-1\n1.4.1 Guidelines\n1-2\n2.0\nGENERAL FORMAT DEFINITION\n2-1\n2.1\nFormat Structure\n2-1\n2.1.1 Information Blocks Definition\n2-1\n2.1.1.1\nControl Blocks\n2-1\n2.1.1.2\nProduct Definition Block\n2-1\n2.1.1.3\nData Description Block\n2-1\n2.1.1.4\nData Block\n2-1\n2.1.2 Blocking Conventions\n2-1\n2.1.2.1 Product Data Set Structure\n2-1\n2.1.2.2 Block Sequencing\n2-1\n2.2\nBlock Format\n2-2\n2.2.1\nBlock Termination\n2-2\n2.2.2\nBlock Size\n2-2\n2.2.3 Block Format Conventions\n2-2\n2.2.3.1 Graphic Display Information\n2-2\n2.2.3.2 Non-graphic Information\n2-2\n2.3 Coordinate System Conventions\n2-3\n-\n2.3.1 Latitude/Longitude Coordinate System\n2-3\n2.3.2\nCartesian Coordinate System\n2-4\n2.3.3\nPixel Coordinate System\n2-4\n3.0\nPRODUCT CONTENT\n3-1\n3.1 Data Categories\n3-1\n3.1.1\nProduct Data Set Control\n3-1\n3.1.2\nProduct Data\n3-1\nV","TABLE OF CONTENTS (cont. )\nPage\n3-1\n3.1.2.1 Formatted Binary Data\n3-1\n3.1.2.2\nVector Graphic Data\n3-1\n3.1.2.3\nAlphanumeric Data\n3-1\n3.1.2.4\nRaster Scan Data\n3-1\n3.1.2.5 Gridded Data\n3-1\n3.2 Mode/Submode Designations\n3-1\n3.2.1 Mode Designations\n3-2\n3.2.2 Submode Designations\n3-2\n3.3 Product Format\n3-2\n3.4 Mode/Submode Combinations\n3-2\n3.4.1 Required and Optional Blocks\n3-2\n3.4.1.1 Systems Product Data Category\n3-2\nFormatted Binary Product Data Category\n3.4.1.2\n3-3\nVector Graphic Product Data Category\n3.4.1.3\n3-3\n3.4.1.4\nAlphanumeric Product Data Category\n3-3\nRaster Product Data Category\n3.4.1.5\n3-4\n3.4.1.6 Gridded (Packed) Product Data Category\n3-4\n3.4.1.7 Gridded (Unpacked) Product Data Category\n3-4\n3.4.2 Allowable Mode/Submode Combinations\n4-1\n4.0\nCONTROL BLOCKS\n4-1\n4.1 Product Identification Block\n4-1\n4.2 End of Product Block\n4-1\n4.3\nClassification Block\n4-1\n4.4 Define Plot Parameters Block\n4-1\n4.5 Define Datawidth/Fieldwidth Block\n5-1\n5.0\nSYSTEMS DATA\n5-1\n5.1 General Information\n5-1\n5.2 Binary Data Block\n6-1\n6.0 FORMATTED BINARY BLOCKS\n6-1\n6.1 Product Definition Block\n6-1\n6.2\nData Description Block\n6-1\n6.3\nData Block\nvi","TABLE OF CONTENTS (cont. )\nPage\n6.4 Presentation of Formatted Binary Data\n6-1\n6.4.1 Formatted Mixed Data\n6-2\n7.0 VECTOR GRAPHIC BLOCKS\n7-1\n7.1 Product Definition Blocks\n7-1\n7.1.1 Vector Graphic Product Definition Block\n7-1\n7.1.1.1\nProduct Area\n7-1\n7.1.1.2\nRegistration\n7-1\n7.1.2 Define Graphics Parameters\nProduct Definition Block\n7-1\n7.2 Data Description Blocks\n7-1\n7.3\nData Blocks\n7-1\n7.3.1 Absolute Vectors Block\n7-1\n7.3.2\nRelative Vectors Block\n7-1\n7.3.3\nCPC Vectors Block\n7-2\n7.3.4 Variable Exception Vectors (VEV) Block\n7-2\n7.3.5 Long/Short Relative Vectors Block\n7-2\n7.3.6\nPoint-Slope Vectors Block\n7-2\n7.3.7\nWind Barbs Vectors Block\n7-2\n7.3.8\nVector (Arrow) Plot Block\n7-3\n8.0\nALPHANUMERIC BLOCKS\n8-1\n8.1\nProduct Definition Block\n8-1\n8.2\nData Description Block\n8-1\n8.3\nData Blocks\n8-1\n8.3.1 Alphanumeric Character Block\n8-1\n8.3.2\nPlot Data Block\n8-1\n8.3.3\nWind Barbs Data Block\n8-1\n8.3.4\nAlphanumeric Data Block\n8-1\n9.0 RASTER SCAN BLOCKS\n9-1\n9.1 Product Definition Blocks\n9-1\n9.1.1 Satellite Product Definition Block\n9-1\n9.1.2 Pixel Product Definition Block\n9-1\nvii","TABLE OF CONTENTS (cont.)\nPage\n9.2 Data Description Block\n9-1\n9.3\nData Block\n9-1\n9.3.1 Block Organization\n9-1\n9.3.1.1 AFGWC Packing Scheme\n9-1\n9.3.1.2 National Weather Service Packing Scheme\n9-1\n9.3.2 Block Length\n9-3\n9.3.2.1 AFGWC Packing Scheme\n9-3\n9.3.2.2 National Weather Service Packing Scheme\n9-3\n10-1\n10.0 GRIDDED DATA BLOCKS\n10.1 Product Definition Block\n10-1\n10.2 Data Description Block\n10-1\n10.2.1 Length and Arrangement of Block\n10-1\n10-1\n10.3\nData Blocks\n10.3.1 Unpacked Gridded Data Block\n10-1\n10-1\n10.3.2 Band Index Data Block\n10.3.2.1 Data Unpacking Method\n10-1\n10-2\n10.4 Grid Conventions\nviii","LIST OF FIGURES\nTitle\nPage\n2.1\nGeneral Block Format\n2-5\n2.2\nGeneral Product Data Set Structure\n2-7\n4.1\nProduct Identification Block Format\n4-2\n4.2\nEnd of Product Block\n4-5\n4.3\nClassification Block\n4-6\n4.4\nDefine Plot Parameters Block\n4-7\n4.5\nDefine Datawidth/Fieldwidth Block\n4-10\n5.1\nBinary Data Block\n5-1\n6.1\nFormatted Binary Product Definition Block\n6-3\n6.2\nFormatted Binary Data Description Block, Option 1\n6-4\n6.3\nFormatted Binary Data Description Block, Option 2\n6-6\n6.4\nFormatted Binary Data Block\n6-8\n7.1\nVector Graphic Product Definition Block\n7-4\n7.2\nDefine Graphics Data Parameters Product Definition Block\n7-7\n7.3\nAbsolute Vectors Block\n7-9\n7.4\nRelative Vectors Block\n7-10\n7.5\nCPC Vectors Block\n7-11\n7.6\nVariation Exception Vectors (VEV) Block\n7-13\n7.7\nLong/Short Relative Vectors Block\n7-15\n7.8\nPoint-Slope Vectors Block\n7-17\n7.9\nWind Barbs Vectors Block\n7-18\nVector (Arrow) Plot Block\n7.10\n7-20\nix","LIST OF FIGURES (cont.)\nPage\nTitle\n8-2\n8.1\nAlphanumeric Product Definition Block\n8.2\nAlphanumeric Characters Block\n8-3\n8-5\n8.3\nPlot Data Block\n8-7\n8.4\nWind Barbs Data Block\n8-9\n8.5\nAlphanumeric Data Block\n9-4\n9.1 Satellite Product Definition Block\n9-7\n9.2 Pixel Product Definition Block\nRaster Scan Data Block\n9-10\n9.3\nPacked Gridded Data Product Definition Block\n10-3\n10.1\n10-6\nBand Index Data Block\n10.2","LIST OF TABLES\nPage\nTitle\n3-6\n3.1 Key to Mode/Submode Designations\n3.2 Mode Designations\n3-7\n3-8\n3.3 Submode Designations\n3.4 Allowable Mode/Submode Combinations\n3-10\nxi","ANNEXES\nTitle\nPage\nA. TERMS, DEFINITIONS AND STANDARD VALUES\nA\n1. Glossary\nA1-1\n2. Mnemonics\nA2-1\nTable A2-1 Symbol, Element and Line Mnemonies\nA2-1\nTable A2-2 Data Block Data Code\nA2-8\nTable A2-3 Other Mnemonies Used in This Report\nA2-11\n3. Constants and Conversion Factors\nB. REFERENCES\nB\nC. CODE TABLES\nC\n1. General\nC1-1\nTable C1-1 Standard ASCII Code (ANSI X3.4-1977)\nC1-1\n2. Meteorological Program\nTable C2-1 ASCII-Symbology Conventions\nC2-1\nTable C2-2 Projection Indicator (PI)\nSet Codes\nC2-2\nTable C2-3 Plot Process Codes\nC2-9\nTable C2-4 Grid Indicator (GI) Set Codes\nC2-10\nTable C2-5 Gray Level Codes\nC2-13\nTable C2-6 Units Code (Octal)\nC2-14\nTable C2-7 Data Representation Codes\nC2-16\n3. Miscellaneous\nxii","ANNEXES (Cont.)\nD. PRODUCT CATALOG NUMBERS\nD\nTable D-1 File Indicators\nD-1\n1. FREE TEXT\n2. OBSERVATIONS (FORMATTED)\n3. VECTOR GRAPHICS\n4. SCAN LINE GRAPHICS\n5. DISPLAY\n6. DISPLAY\n7. MISCELLANEOUS\nE. LOCATION IDENTIFIERS\nE\n1. General\n2. Meteorological Program\n3. Miscellaneous\nF. EXAMPLES\nF\n1. Vector Graphic Product Structure\nF-1\n2. Alphanumeric Product\nF-4\n3. Surface Formatted Binary Product\nF-6\n4. Upper Air Formatted Binary Product\nF-9\n5. Unpacked Gridded Data Product\nF-12\nxiii","1.0 INTRODUCTION\n1.1 Purpose. This Weather Data Exchange Format Document presents a common\nset of formats to be used for the presentation of weather data among Federal\nagencies. The document includes formats which meet current and planned require-\nments of the National Weather Service (NWS), United States Air Force (USAF),\nUnited States Navy (USN), and Federal Aviation Administration (FAA).\nA potential user should not attempt to apply specific formats without: (1)\na thorough knowledge of the format contents, (2) an understanding of the product\ndata set format syntax necessary to organize the data, and (3) an understanding\nof general techniques as applied to automated computer graphics. A review of\nAnnex F before and during the reading of this document will greatly aid the user\nin understanding the formats.\n1.2 Objective. The objectives of this standard formats document are:\nA. To provide a level of data structuring above the telecommunications\nthat is not dependent on the networking and data link procedures.\nB.\nTo provide a format that will support existing products and message\ndata, both graphic and nongraphic.\nC.\nTo provide a device independent format that will allow for expansion\nto handle new data structures or graphics devices without having to\nredefine the general structure of the format.\nD.\nTo provide a format that will be convenient for the host processor to\ngenerate and for the receiving hardware to process.\nE. To provide a format that readily allows receivers to bypass data\nformats not usable or necessary at the receiving station.\nF. To provide a format which is byte oriented with 8 bits per byte\n(octets).\n1.3 Scope. This document specifies the format structure for data trans-\nfer, identifies categories of products covered by the formats and defines the\nformats for each data category to the byte level. Telecommunications protocols\nare not covered in this document.\n1.4 Essential Principals. In order to facilitate automated processing by\ncomputer at the sites being serviced by this format, the following principals\nmust apply:\nA.\nThe defined meaning of an element must remain absolutely constant,\nregardless of the mode/submode block in which it appears. For\nexample: Format elements which are common to more than one mode/\nsubmode block must appear in those blocks as defined:\n1. In their defined order.\n2. In their defined format.\n3. Having constancy of meaning regardless of block type.\n1-1","B. The defined field size (in either bits or bytes) for an element must\nremain constant throughout the code.\nRedundancy and duplication shall be avoided. This especially applies\nC.\nto defining \"new\" elements or new block types (mode/submode) which are\nnearly a duplication of an existing element or block type. For\nexample: Rather than defining a new grid type code, the existing\ncodes should be used by adding to its definition.\nFormats shall be \"self-contained\" as far as technically feasible.\nD.\nThat is, they should carry within the code all that is necessary to\ndecode and use the information without reference to assumed or\npreviously understood rules not contained in this publication.\nFormat elements must always be general rather than device specific or\nE.\nmachine specific. For example, a number that must be represented in\nfloating point format as an element should have field lengths which\nconform easily to byte and/or byte pair boundaries. The format of\nsuch elements should fall naturally into the structure of the block\nwhich holds them.\n1.4.1 Guidelines. In order to maintain fidelity with Objective A, Section\n1.2 with respect to \"data structuring above the telecommunications level,\" it is\nimportant to adhere to the following guidelines:\nElements included in this document are present for the purpose of non-\nA.\ntelecommunications processing. These data are the innermost part of\nan envelope whose outer parts are concerned with telecommunications\nprocessing.\nB. Changes or enhancements to the telecommunications sections of the\nproduct transmission are completely independent of changes to the\nformats contained herein. Conversely, changes to these formats should\nnot impact in any way the telecommunications format.\n1-2","2.0 GENERAL FORMAT DEFINITION\n2.1 Format Structure. The format structure is constructed with\ninformation blocks. Information blocks provide control information and contain\ndata. Figure 2.1 displays the general format of information blocks. A specific\ngrouping of these blocks is used to create a product and is considered a product\ndata set.\n2.1.1 Information Blocks Definition. An information block is a series of\nbytes identifying, controlling, or containing information used to create\nproducts. These blocks are characterized as control blocks, product definition\nblocks, data description blocks and data blocks.\n2.1.1.1 Control Blocks. The control blocks are Product Identification,\nEnd of Product and parameter control blocks. The Product Identification Block\nis a standard block used for all products. Its purpose is to convey the\ninformation needed to uniquely identify each product so that appropriate\nprocessing routines may be initiated by the receiving system. The End\nof\nProduct block is a standard block that signifies the end of the product data\nset. The other control blocks provide product data set wide control of\nparameters in the data blocks.\n2.1.1.2 Product Definition Block. The Product Definition Block shall\ncontain all information required to define the nature of the product being\ntransferred (product area, scale, orientation, etc.)\n2.1.1.3 Data Description Block. The Data Description Block shall contain\nall information required to describe the contents of the data block(s) that\nfollow (number and type of elements, element arrangement, units, etc.) The\ndata description block shall be used when additional information about the\nstructure and content of the data block(s) is required.\n2.1.1.4 Data Block. The Data Block(s) shall contain the data in the\nformat, units, etc., specified by the data description block, if not inherent in\nthe data block itself.\n2.1.2 Blocking Conventions. Multiple information blocks are used to fully\ndefine a product.\n2.1.2.1 Product Data Set Structure. The product data set components shall\nbe: a Product Identification Block; a Product Definition Block; one or more sets\nof control, data description, and data blocks; and each product data set shall\nbe terminated by an End Of Product Block. Figure 2.2 displays the general\nProduct Data Set Structure.\n2.1.2.2 Block Sequencing. The Product Identification Block shall always\nbe the first block in the product data set. Define Plot Parameters and Define\nDatawidth/Fiel dwidth blocks may be interspersed with the data blocks and may\nappear anywhere in the product data set after the Product Identification block\nbut before the data to which it applies. Multiple sets of Data Description\nBlocks (when used), followed by one or more Data Blocks, may be used as required\nby the product originator to define all components of the product.\n2-1","2.2 Block Format. In general, each block shall contain the following\nfields: a LENGTH field, the MODE and SUBMODE fields, the DATA field, and a\nCHECKSUM field. These fields are defined in the notes following Figure 2.1.\nThe LENGTH and CHECKSUM fields provide internal block information. The MODE and\nSUBMODE fields indicate the general content of the DATA field in the block.\n2.2.1 Block Termination. The LENGTH field identifies the end of the block\nby providing a count of all byte pairs contained in the block. If the LENGTH\nfield is not used, termination of a block can be accomplished by setting the\nmost significant bit of the last byte in the data field. The originator must be\nable to guarantee that all other bytes in the data field have a zero in the most\nsignificant bit; otherwise, the LENGTH field will be necessary. In the case of\nnon-graphic data, where a subset of the ASCII code is specified, ETX and ETB are\nused to end a block. (See Section 2.2.3.2B.)\n2.2.2 Block Size. Block length shall be variable but shall not exceed\n4096 bytes, including the LENGTH and CHECKSUM fields when used. Multiple data\nblocks shall be used as required by the product originator to conform to the\nblock length restriction and enhance circuit efficiency.\n2.2.3 Block Format Conventions. The following general format conventions\nshall be observed within all blocks:\nA. Byte ( and bit) numbering shall be referenced to byte (bit) zero (0),\ni.e., the second byte (bit) is numbered one (1) The byte order shall be left\nto right and the bit order shall be right to left.\nB. All fields in the blocks shall be in one or more bytes unless otherwise\nspecified in the block format or the data description block.\nC. All block formats shall be arranged into two byte pairs with the bytes\nordered left to right.\nD. The LENGTH and CHECKSUM fields shall be used as required by the product\noriginator. The presence or absence of the LENGTH and CHECKSUM fields shall be\nindicated by the flag in the LENGTH field. If the LENGTH and CHECKSUM fields\nare not used, the two left-most bits in byte zero of the block (i.e., the two\nmost significant bits in the MODE bytes) become the flag bits.\n2.2.3.1 Graphic Display Information. The data contained in blocks which\nare display-oriented shall observe the following conventions:\nA. All binary data shall be in two's complement form.\nB. Binary data shall be right justified and zero filled.\nC. All data is represented in octal notation unless otherwise noted.\n2.2.3.2 Nongraphic Information. The data contained in non-graphic blocks\n(e.g., man-readable messages) shall observe the following conventions:\n2-2","A. All nongraphic data shall be seven (7) bit ASCII (ANSI X3.4-1977).\nParity, if used, is transparent to these formats, except when the uppermost bit\nof the last data byte is being used to identify the last byte for recognition of\nblock termination. (See Section 2.2.1) An interagency common assignment of\nASCII control characters to represent symbolic information weather\nsymbols) is found in Annex C (Table C2-1).\nB. Alphanumeric data shall be left justified within a field and blank\nfilled. When using ASCII code, the following conventions will apply to separate\ninformation within and terminate a block. The control character RS will be used\nto separate records within a data block. The control character ETB will be used\nat the end of blocks which are not the final block of a product data set. The\ncharacter ETX will be the final character of an ASCII block which is the final\nblock in a product data set. The most significant bit of the final byte (ETB or\nETX) in the block may also be used for termination of a block when the previous\nbytes contain zeros in the most significant bit.\n2.3 Coordinate System Conventions. Many of the products transmitted in the\nformats specified in this document use one of three coordinate systems to\nregister and locate features to their proper position on a map or background.\nOnce the coordinate system is selected, that system is then used for all\nsubsequent coordinate references. The user needs to have a thorough understand-\ning of the particular coordinate system being used and the implication that\nsystem has on proper data interpretation. The coordinate system in use for a\nproduct is indicated by a COORDINATE FLAG code found in the product definition\nblock. The three coordinate systems which can be used are:\nLatitude/Longitude\nCartesian\nPixel.\nThe choice of coordinate systems affects interpretation of the following product\nregistration information (applicable mode/submodes appear in parenthesis):\n(4/20, 7/20)\nReference M,1 Coordinates\nM,N Maximum\n(4/30)\nM,N Center\n(4/30)\n(4/1, 4/2, 4/3, 4/4, 4/5, 4/6, 4/7,\nM,N Coordinates\n4/10, 5/1, 5/2, 5/3)\nDelta M,N\n(4/2, 4/5, 5/1)\n(7/20)\nISTART, JSTART\n(7/20)\nIPOLE, JPOLE\nThe explicit meaning of the coordinate flag remains in effect until changed by a\nnew coordinate flag presented in a new product definition block for the product\ndata set in question.\n2.3.1 Latitude/Longitude Coordinate System (Coordinate Flag = 0) With\nthis system, all product registration data use latitude and longitude to\nposition features. All grid coordinate references appear in standard latitude\nand longitude on earth.\n2-3","2.3.2 Cartesian Coordinate System (Coordinate Flag = 1). Many of the\nnumerical models used in meteorology use some form of Cartesian coordinate grid\nsystem for mathematical manipulations. Because of this, it is convenient to\noutput products with data registered to these Cartesian grid points. The array\nof points themselves are created projecting the earth onto a flat plane, select-\ning a coordinate system origin, and defining an array of uniformly spaced\npoints. The agencies involved in producing the products described in this\ndocument each have their own unique Cartesian coordinate grid systems but they\nare related. Mathematical equations can be used to convert from one system to\nthe other but the user must have basic knowledge concerning the grid system of\nthe source. This information includes:\nProjection\nGrid density\nIndexing conventions\nOrigin point\nLocation of pole (in Cartesian coordinates)\nStandard longitude\nU,V-Wind component conventions.\nKnowing these, the user can properly interpret the coordinate information\nimbedded in the product.\n2.3.3 Pixel Coordinate System (Coordinate Flag = 2). In some cases, it is\nconvenient to send product coordinate information relative a logical display\nreference system, called pixel in this case. The origin (0,0) of the logical\ndisplay space is the lower left corner and the indexing convention follows the\nright hand rule. Products are described relative to this logical display space\nin terms of horizontal (I-direction or X-direction) and vertical (J-direction or\nY-direction) displacement from the origin. This pixel grid coordinate system\ncan be translated by the user into whatever system needed for product\nmanipulation and display.\n2-4","2**15\n2**0\nFF :\nLENGTH (I)\nMODE\nSUBMODE\n.\nDATA FIELD\nLAST BYTE\n:\nCHECKSUM\nFigure 2.1\nGeneral Block Format\nMode x, Submode Y\n2-5","NOTES: Figure 2.1 General Block Format, Mode X, Submode Y\n1. FF = Flag: The Flag field is a two-bit LENGTH/CHECKSUM indicator. Possible\ncombinations of these two bits are:\nCHECKSUM FIELD\nFlag Bits\nLENGTH FIELD\n00\nYES\nYES\nNO\n01\nYES\n11\nNO\nNO\nIf the first Flag bit is one (1), the lower six bits of the byte will\ncontain the Mode. The Flag bit combination 10 is not used as an indicator since\nthere will never be a CHECKSUM field if the LENGTH field is not present. Blocks\nthat contain data where the most significant bit of a byte could contain a one\n(1) shall always have a LENGTH field.\n2. LENGTH: The LENGTH is the total number of two byte pairs in the current\nblock, including the bytes containing the LENGTH and CHECKSUM fields if present.\n3. The notation (I) indicates an unsigned integer quantity, e.g., LENGTH (I)\nindicates the LENGTH is an integer number.\n4. MODE: The MODE indicator byte is contained in all transmission blocks and\ntells to the receiver the type of block being transferred. Note that the most\nsignificant bit will be a one (1) if LENGTH and CHECKSUM fields are not present.\n5. SUBMODE: The SUBMODE is used to classify each MODE into its logical\nsubdivisions for the purpose of clarity in defining a block of data within a\ntransmission mode.\n6. DATA FIELD: The DATA FIELD bytes contain information about the data and/or\nthe data itself. Each block (i.e., MODE and SUBMODE combination) has\ninformation defined in this field for specific applications. The DATA FIELD\nwill end on a two byte boundary, with binary data being zero filled and\nalphanumeric data being blank filled if necessary.\n7. CHECKSUM: The CHECKSUM is a two's complement 16 bit field containing the\narithmetic sum of all 16 bit byte pairs in the block with no end around carry.\nAdding all the byte pairs in a Mode/Submode that contains a CHECKSUM field will\nproduce a sum equal to zero.\n2-6","FF\nLENGTH\nMODE\nSUBMODE\nPRODUCT IDENTIFICATION\nBLOCK\nPRODUCT IDENTIFICATION DATA\nSEE FIGURE 4. 1\nCHECKSUM\nFF\nLENGTH\nMODE\nSUBMODE\nPRODUCT DEFINITION\nBLOCK\nPRODUCT DEFINITION DATA\nSEE PARAGRAPH 2.1.1.2\nCHECKSUM\nFF\nLENGTH\nMODE\nSUBMODE\nDATA DESCRIPTION\nAND DATA BLOCK SET 1\nDATA DESCRIPTION BLOCK\nSEE PARAGRAGH 2.1.1.3\nCHECKSUM\nDEFINE PLOT PARAMETERS\nSEE FIGURE 4.4\nDEFINE DATAWIDTH/FIELDWIDTH\nSEE FIGURE 4.5\nDATA BLOCK 1\nDATA DESCRIPTION\nAND DATA BLOCK SET n\nDATA BLOCK m\nEND OF PRODUCT BLOCK\nSEE FIGURE 4.2\nFigure 2.2\nGeneral Product Data Set Structure\n2-7","3.0 PRODUCT CONTENT\n3.1 Data Categories. The formats contain information blocks of two basic\ntypes: 1) product data set control and 2) product data.\n3.1.1 Product Data Set Control. The product data set control information\nincludes the blocks for beginning and ending the product data set, for defining\nparameter values and fields within the product data set, and which contain other\nproduct related information. Also, user specific internal system data control\nis provided for.\n3.1.2 Product Data. The product data can be specified by the following\ncategories:\nA. Formatted Binary\nB. Vector Graphic\nC. Alphanumeric\nD. Raster Scan\nE. Gridded\n3.1.2.1\nFormatted Binary Data. Formatted binary data consists of\nmachine-readable decoded weather observation/forecast data.\n3.1.2.2 Vector Graphic Data. Vector graphic data shall be used to\ndescribe weather maps/charts. Vector graphic data includes vectors, graphic\nsymbols and geographic background.\n3.1.2.3 Alphanumeric Data. Alphanumeric (A/N) data shall be used for\nman-readable messages consisting of A/N character strings and labels for display\nproducts.\n3.1.2.4 Raster Scan Data. Raster scan data shall be pixel data describing\nvisual imagery such as satellite pictures, radar pictures, gray level imagery or\nfacsimile images. This data may be in either packed or unpacked form.\n3.1.2.5 Gridded Data. Gridded data shall consist of sets of machine\nreadable weather data located at uniformly spaced geographical points.\n3.2 Mode/Submode Designations. All format blocks are identified by mode\nand submode values. These values are octal integers. The key to general\nmode/submode assignments is found in Table 3.1. In general, mode numbers\nrepresent data categories and submode numbers represent the specific product\ndefinition, data description and data blocks within a data category. Currently\ndefined modes and submodes are shown in Tables 3.2 and 3.3; however, new\nmode/submode combinations shall be added based on agency needs and committee\nagreement.\n3.2.1 Mode Designations. The data categories in Section 3.1.2 are\nidentified by mode numbers. Mode 1 contains control blocks, Mode 2 is for\nindividual user internal system applications, and Modes 3 through 7 are for the\nproduct data. See Table 3.2.\n3-1","3.2.2 Submode Designations. Table 3.3 presents a listing of the submodes\nwithin each mode and gives a reference to corresponding figures.\n3.3 Product Format. A product data set is formed to create a product. A\ncomplete product shall consist of all information required to describe a bounded\ngroup of related data. A product data set contains the product identification,\ndefinition, data description and data blocks (the format specified in Section\n2.0) as necessary to create the desired product. The product definition block\nidentifies the type of product (e.g., alphanumeric message, graphic display, or\nsatellite image, etc.). Data descriptions and data blocks from any data\ncategory may be included in a single product data set if that data is needed for\nthe product (e.g., alphanumeric labels applied to a graphic product).\nA\nrepresentative example of a vector graphic product is found in Annex F.\n3.4 Mode/Submode Combinations. As a rule, the mode/submode designations\nfor a product data category will not be mixed with designations for a different\nproduct data category. For example, vector graphic data and gridded data will\nnot appear in the data set defining one product.\n3.4.1 Required and Optional Blocks. By convention, the following shows\nthe required and optional blocks for each of the product data categories.\n3.4.1.1 Systems Product Data Category\nA. Required Blocks\nMode 1/Submode 1\nMode 2/User defined Submode\nMode 1/Submode 2\nB. Optional Blocks\nMode 1/Submode 3\n3.4.1.2 Formatted Binary Product Data Category\nA. Required Blocks\nMode 1/Submode 1\nMode 3/Submode 1\nMode 1/Submode 2\nB. Optional Blocks\nMode 1/Submode 3\nMode 3/Submode 20\nMode 3/Submode 21\nMode 3/Submode 22\nC. Note: Mode 3/Submode 21 or Mode 3/Submode 22 is required if the format\nof the data presented in Mode 3/Submode 1 has not been specified external to the\nproduct by mutual agreement of the exchanging agencies controlling the weather\ninformation systems involved in the data exchange.\n3-2","3.4.1.3 Vector Graphic Product Data Category\nA. Required Blocks\nMode 1/Submode 1\nOne of the following:\nMode 4/Submode 20\nMode 4/Submode 30\nOne or more of the following:\nMode 4/Submode 1\nMode 4/Submode 2\nMode 4/Submode 3\nMode 4/Submode 5\nMode 4/Submode 6\nMode 1/Submode 2\nB. Optional Blocks\nMode 1/Submode 3\nMode 1/Submode 4\nMode 4/Submode 4\nMode 4/Submode 7\nMode 4/Submode 10\nMode 5/Submode 1\nMode 5/Submode 2\nMode 5/Submode 3\n3.4.1.4 Alphanumeric Product Data Category\nA. Required Blocks\nMode 1/Submode 1\nMode 5/Submode 4\nMode 1/Submode 2\nB. Optional Blocks\nMode 1/Submode 3\nMode 5/Submode 20\n3.4.1.5 Raster Product Data Category\nA. Required Blocks\nMode 1/Submode 1\nOne or both of the following:\nMode 6/Submode 20\nMode 6/Submode 30\nMode 6/Submode 1\nMode 1/Submode 2\n3-3","B. Optional Blocks\nMode 1/Submode 3\nMode 1/Submode 5\nC. Note: Mode 1/Submode 5 is required if the data presented in Mode\n6/Submode 1 has not been specified external to the product as a default\ndatawidth and fieldwidth by mutual agreement of the exchanging agencies\ncontrolling the weather information systems involved in the data exchange.\n3.4.1.6 Gridded (Packed) Product Data Category\nA. Required Blocks\nMode 1/Submode 1\nMode 7/Submode 20\nMode 7/Submode 1\nMode 1/Submode 2\nB. Optional Blocks\nMode 1/Submode 3\nMode 1/Submode 5\nC. Note: Mode 1/Submode 5 is required if the data presented in Mode\n7/Submode 1 has not been specified external to the product as a default\ndatawidth and fieldwidth by mutual agreement of the exchanging agencies\ncontrolling the weather information systems involved in the data exchange.\n3.4.1.7 Gridded (Unpacked) Product Data Category\nA. Required Blocks\nMode 1/Submode 1\nMode 7/Submode 20\nMode 3/Submode 1\nMode 1/Submode 2\nB. Optional Blocks\nMode 1/Submode 3\nMode 3/Submode 21\n3.4.2 Allowable Mode/Submode Combinations. Table 3.4 summarizes the\nallowable combinations of defined modes and submodes for the various mode\ndesignations.\n3-4","Table 3.1\nKey to Mode/Submode Designations\nNumber (Octal)\nType of Information\nModes\n001-002\nProduct Control/Internal System Data\nSubmodes\n001-017\nControl or Data Blocks\nModes\n003-077\nProduct Type (only 3-7 are currently\nassigned)\nSubmodes\n001-017\nData Blocks (DB)\n020, 030,\n070\nProduct Definition Blocks (PDB)\n021-027, 031-037,\nData Description Blocks (DDB)\n..., 071-077\nassociated with PDB, (e.g., 21-27 => 20)\n100-377\nUnassigned, to be designated if the\nassigned ranges are exhausted.\n3-5","Table 3.2\nAssigned Mode Designations\nMode (Octal)\nDefinition\nProduct Data Set\n001\nControl\nSystems Data\n002\nFormatted Binary*\n003\nVector Graphic\n004\nAlphanumeric\n005\nRaster Scan\n006\nGridded*\n007\n*Note: Packed gridded data is accommodated under\nMode 7, unpacked gridded data is accommodated under\nMode 3.\n3-6","Table 3.3\nAssigned Submode Designations\nDescription\nSubmode\nFigure No.\n(Octal)\nMode 1 Product Data Set Control\nProduct Identification Block\n1\n4.1\nEnd of Product Block\n2\n4.2\nClassification Block\n3\n4.3\nDefine Plot Parameters Block\n4\n4.4\nDefine Datawidth/Fieldwidth Block\n5\n4.5\nMode 2 Systems Data\nBinary Data Blocks\nUser Definable\n5.1\nMode 3 Formatted Binary\nFormatted Binary Product Definition Block\n20\n6.1\nFormatted Binary Data Description Block,\n21\n6.2\nOption 1\nFormatted Binary Data Description Block,\n22\n6.3\nOption 2\nFormatted Binary Data Block\n1\n6.4\nMode 4 Vector Graphic\nGraphics Product Definition Block\n20\n7.1\nDefine Graphics Parameters Block\n30\n7.2\nAbsolute Vectors\n1\n7.3\nRelative Vectors\n2\n7.4\nCPC Vectors Block\n3\n7.5\nVariable Exception Vectors (VEV) Block\n4\n7.6\nLong/Short Relative Vectors Block\n5\n7.7\nPoint/Slope Vectors Block\n6\n7.8\nWind Barbs Vectors Block\n7\n7.9\nVector (Arrow) Plot Block\n10\n7.10\n3-7","Table 3.3 (cont.)\nAssigned Submode Designations\nFigure No.\nSubmode\nDescription\n(Octal)\nMode 5 Alphanumeric\n8.1\nAlphanumeric Product Definition Block\n20\n8.2\n1\nAlphanumeric Character Block\n8.3\n2\nData Plot Block\n8.4\n3\nWind Barbs Data Block\n8.5\n4\nAlphanumeric Data Block\nMode 6 Raster Scan\n9.1\n20\nSatellite Product Definition Block\n9.2\n30\nPixel Product Definition Block\n9.3\n1\nRaster Scan Data Block\nMode 7 Gridded\n10.1\n20\nGridded Product Definition Block\n10.2\n1\nBand Index Data Block*\n#Packed gridded products. See Section 10.\n3-8","Table 3.4\nAllowable Mode/Submode Combinations\nProduct Data Category\nMode/Submode Systems Formatted Binary Vector Graphic A/N Raster Gridded\nProduct Data Set Control\n1/1\nr\nr\nr\nr\nr\nr\n1/2\nr\nr\nr\nr\nr\nr\n1/3\no\no\no\nO\no\no\n1/4\nO\n1/5\nO (1)\no\nSystems Data\n2/User\nDefined\nr\nFormatted Binary\n3/1\nr (2)\nr\n3/20\no\n3/21\nO (2)\nO\n3/22\no(4)\nVector Graphic\n4/1\nr (3)\n4/2\nr (3)\n4/3\nr (3)\n4/4\no\n4/5\nr (3)\n4/6\nr (3)\n4/7\no\n4/10\no\n4/20\nr (3)\n4/30\nr (3)\nAlphanumeric\n5/1\nO\n5/2\nO\n5/3\no\n5/4\nr\n5/20\nO\n3-9","Table 3.4 (cont.)\nAllowable Mode/Submode Combinations\nProduct Data Category\nFormatted Binary Vector Graphic A/N Raster Gridded\nMode/Submode Systems\nRaster Scan\n6/1\nr\nr (3)\n6/20\nr (3)\n6/30\nGridded (Packed)\nr (1)\n7/1\n7/20\nr\nGridded (Unpacked)\nr (2)\n3/1\n7/20\nr\no (2)\n3/21\nNOTES: Table 3.4\n- Mode/submode is required\nr\n- Mode/submode is optional\no\n(1) - Used in packed gridded products.\n(2) - Used in unpacked gridded products.\n(3) - Only one of these mode/submodes will be used.\n(4) - Used in formatted mixed products.\n3-10","4.0 CONTROL BLOCKS\n4.1 Product Identification Block. This block is required for all data\ntypes and shall be formatted as shown in Figure 4.1. The data field shall\nidentify the origin of the product, the classification, retention time, product\nidentifier, and file time. These fields shall be as defined in Figure 4.1\nexcept as otherwise noted below or under individual data type format\ndiscussions.\n4.2 End of Product Block. The End of Product Block format is shown in\nFigure 4.2. This block shall be standard for all data types.\n4.3 Classification Block. The Classification Block format is shown in\nFigure 4.3. This block shall be used if additional information regarding the\nclassification of the product data set (other than that information provided in\nthe CLASSIFICATION byte of the Product Identification Block - Figure 4.1) is\nrequired.\n4.4 Define Plot Parameters Block. This block shall be formatted as shown\nFigure 4.4. When used the fields required will be filled and all other\nin\nfields will be either zero or blank filled, unless the length is used to\nforeshorten the block when the latter fields are not needed. IF LENGTH is not\nused, the full format is required. The Define Plot Parameters Block may be used\nprior to any data block to indicate the settings of display parameters. Once\nset, the parameters remain in that state until superseded by another Define Plot\nParameters Block.\n4.5 Define Datawidth/Fieldwidth Block. The Define Datawidth/Fiel dwidth\nBlock shall be formatted as shown in Figure 4.5. It may be used to redefine the\nnumber of bits allocated to (field width) and used by (data width) each data\nelement in the specified mode/submode. The following rules shall apply to the\nuse of this block:\nA. Redefined Datawidth/Fieldwidth values shall not apply to the LENGTH,\nMODE, SUBMODE, CHECKSUM, or other informational elements in the specified\nMode/Submode, i.e., redefined values apply only to the data itself.\nB. Redefined values shall remain in effect for all subsequent blocks with\nthe specified Mode/Submode until reset by another Define Datawidth/Fieldwidth\nBlock or End of Product Block, whichever comes first in the product data set\nsequence.\nC. The Define Datawidth/Fiel dwidth Block may be inserted anywhere in the\nproduct data set but applies only to the blocks that immediately follow it in\nthe product data set sequence.\nD. Each block may be used to redefine values for one Mode/Submode.\nAdditional blocks may be used, as required, to redefine values for additional\nmode/submode blocks. However, these blocks must be inserted immediately before\nthe Mode/Submode to which the redefined Fieldwidth and Datawidth apply.\n4-1","FF :\nLENGTH (I)\n001\n001\nCHARACTER 1\nCHARACTER 2\nOriginator\nIdentification\nCHARACTER 4\nCHARACTER 3\nCLASSIFICATION\nRETENTION TIME\nFILE INDICATOR\nCHARACTER 2\nCHARACTER 4\nCHARACTER 3\nProduct\nCHARACTER 6\nCHARACTER 5\nIdentifier\nCHARACTER 8\nCHARACTER 7\nCHARACTER 9\nCHARACTER 10\nYEAR\nProduct\nMONTH\nDAY\nFile Time\nHOUR\nMINUTE\nCHECKSUM\nFigure 4.1\nProduct Identification Block\nMode 1, Submode 1\n4-2","NOTES: Figure 4.1: Product Identification Block; Mode 1, Submode 1\n1. Originator Identification: A four character identifier of the facility that\ngenerates or compiles the product.\n2. CLASSIFICATION: The classification code is a single ASCII character defin-\ning the classification for this product as follows:\nU = Unclassified\nC = Confidential\nS = Secret\nT = Top Secret\nE = Encrypt for Transmission Only (EFTO)\nIf additional information is required, a classification Block shall be used.\n(Section 4.3.)\n3. RETENTION TIME: The RETENTION TIME is the default time, in days, the system\nshall use to retain the product before purging it. This byte will contain 377\n(octal) or all binary zeros when this value is not furnished.\n4. FILE INDICATOR: The FILE INDICATOR byte specifies the naming convention\nused to identify the product being transmitted. This byte plus the succeeding\nnine bytes contain the product identifier. The indicator is defined as follows:\nFile Indicator (Octal)\nFile Naming Convention\n000 to 077\nThe file indicator is a value determined\nby interagency agreement. The values are\nfound in Annex D. The remaining nine\ncharacters are defined as:\nCHARACTERS 2-5:\nCatalog Number (See\nAnnex D). .\nCHARACTERS 6-8:\nThree character\nnumber representing\nthe time in hours\nfrom product genera-\ntion time.\nCHARACTERS 9-10:\nTwo ASCII characters\ndefined for products\nthat are transmitted\nwithout a back-\nground. Interagency\ncommon background\ndescriptions are\nused. (See Annex C,\nTable C2- )\n4-3","The file indicator is the first ASCII\n100 to 177\ncharacter of a 10 character product\nidentifier. The file name is left\njustified, blank filled. The following\nASCII charater assignments are given to\neach agency:\nAir Force\nA-G\nNWS\nH-M\nFAA\nN-S\nNavy\nT-Z\nIf the file indicator contains the value\n177, the file name is for internal use\nonly.\nReserved for future\n200 to 377\n5. Product File Time: The Product File Time shall consist of a full century\nyear (16 bit integer), month, day, hour, and minute (8 bit integers).\nIt\nrepresents a means of further identifying products with identical Product\nIdentifiers. Unless otherwise specified, this time shall be the date/time the\nproduct was generated.\n4-4","FF :\nLENGTH (I)\n001\n:\n002\nCHECKSUM\nFigure 4.2\nEnd of Product Block\nMode 1, Submode 2\n4-5","FF :\nLENGTH (I)\n001\n003\nCHARACTER 1\nCHARACTER 2\nCHARACTER 4\nCHARACTER 3\nLAST CHARACTER\nCHECKSUM\nFigure 4.3\nClassification Block\nMode 1, Submode 3\nNOTES: Figure 4.3: Classification Block; Mode 1, Submode 3\n1. CHARACTER: The information in ASCII code.\n2. This block follows the rules for non-graphic blocks. See Section 2.2.3.2.\n4-6","FF :\nLENGTH (I)\n001\n004\nZ ZOOM THRESHOLD\nZOOM FACTOR\nPLOT COLOR\nBACKGROUND COLOR\nLINE CHARACTER\nLINE WIDTH\nCHARACTER 1\nCHARACTER 2\nLine Mnemonic\nCHARACTER 3\nCHARACTER 4\nCHECKSUM\nFigure 4.4\nDefine Plot Parameters Block\nMode 1, Submode 4\n4-7","NOTES: Figure 4.4: Define Plot Parameters Block; Mode 1, Submode 4\n1. Z = Zoom Disable: If Z=1, the displayable data will be invariant in display\nsize regardless of zoom selection. If Z=0, displayed data are sized according\nto zoom selection.\n2. ZOOM THRESHOLD: The ZOOM THRESHOLD is the minimum magnification that may be\napplied to the product within the constraints of the data density from which the\nproduct was built. This value is the denominator of the fractional area of the\nentire viewing space. Currently assigned codes (decimal) which are representa-\ntive of the zoom value are:\n00 - Display at all zoom levels (default)\n01 - Display at 1X or higher magnification\n02 - Display at 2X or higher magnification\n03 - Display at 3X or higher magnification\n04 - Display at 4X or higher magnification\n16 - Display at 16X or higher magnification\n3. ZOOM FACTOR: An optional zoom (magnification) factor to be assigned to\nstrings selectively at a local level. These values range from 0-255 (decimal). .\n0 - No zoom (default)\n1 - 1X\n2 - 2X\n3 - 3X\n4. PLOT COLOR and BACKGROUND COLOR: These values range from 0 to 255\n(decimal) . Application of National Bureau of Standards (NBS) color standards is\nto be determined.\n5. LINE CHARACTER: Assigned values are:\n0 - Continuous (default)\n1 - Dotted line (alternate pixels)\n2 - Dashed line (short dashes)\n3 - Dashed line (long dashes)\n4 - Dotted line (every 4th pixel)\n5 - Symbolic line\n6. LINE WIDTH: This value indicates the thickness of line in pixels.\n7. Line Mnemonic: Line mnemonics are specified in Tables A2-1 and A2-2.\n4-8","8. Values defined by this submode are effective on all subsequent modes until\nredefined.\n9. This block can be shortened by using a LENGTH value less than the maximum\nnumber of byte pairs shown in the figure. The fields past the LENGTH count will\nbe truncated and the information they control not changed.\n4-9","FF :\nLENGTH (I)\n001\n005\nf FIELDWIDTH\nd| DATAWIDTH\nMODE\nSUBMODE\nCHECKSUM\nFigure 4.5\nDefine Datawidth/Fieldwidth Block\nMode 1, Submode 5\nNOTES: Figure 4.5: Define Datawidth/Fieldwidth Block; Mode 1, , Submode 5\n1. f: If this bit is set, the data will be continuous and cross byte and\nbyte/pair boundaries.\n2. FIELDWIDTH: An integer number that defines the number of bits allocated to\neach data element in the specified mode/submode. The legal range is 1 through\n16 (decimal) .\n3. d: When this bit is set, the data will be left justified in the field\ndefined by FIELDWIDTH; i.e., empty spaces will trail the data.\n4. DATAWIDTH: An integer number that defines the number of bits used by the\nactual data within the FIELDWIDTH. The legal range is 1 through FIELDWIDTH.\nExample: If the data are three bits wide and are repeated every four bits, then\nFIELDWIDTH = 4, DATAWIDTH = 3.\n5. MODE and SUBMODE: The mode and submode to which the redefined fieldwidth\nand datawidth apply.\n4-10","5.0 SYSTEMS DATA\n5.1\nGeneral Information.\nThis mode is provided to support the\ntransmission of system or application binary data. The submodes are user\ndefinable internally within the user system and not intended for any other\nagency use.\n5.2 Binary Data Block. The format for this block is depicted in Figure\n5.1. No Product Definition or Data Description blocks are necessary with this\ndata block.\nFF|\nLENGTH (I)\n002\n\"n\"\n\"n\" = user\ndefinable\nBYTE 1\nBYTE 2\nBYTE 3\nBYTE 4\nLAST BYTE\nCHECKSUM\nFigure 5.1\nBinary Data Block\nMode 2, Submode \"n\"\n5-1","6.0 FORMATTED BINARY BLOCKS\n6.1 Product Definition Block. This block shall be an 18 byte block,\nincluding the LENGTH and CHECKSUM fields. The specific format and content shall\nbe as shown in Figure 6.1.\n6.2 Data Description Block. The Formatted Binary Data Description blocks,\n(Option 1 and Option 2) shown in Figure 6.2 and in Figure 6.3, act as data\ninterpretation tables for the data in the following binary data block(s). They\ndescribe the data in the Formatted Binary Data block(s) in sufficient detail to\nallow the receiver to use the data. The length of the description blocks shall\ndepend on the number of repeating data sections required to define the product.\n(See Note 3 for Figure 6.2 or Figure 6.3.)\n6.3 Data Block. The Formatted Binary Data block shall be formatted as\nshown in Figure 6.4. The data field shall be formatted as specified in the\nFormatted Binary Data Description blocks, Option 1 or Option 2, whichever is\nappropriate.\n6.4 Presentation of Formatted Binary Data. While the data description\nblocks serve as data interpretation tables for the data block(s) which may\nfollow, there are a number of ways for presentation of element data in the\nformatted binary data block. Most element data lends itself to numeric (binary)\npresentation (e.g., temperature, heights, etc.) while other element data lends\nitself to presentation as ASCII characters (e.g., station ICAO call letters,\npresent weather). Agencies have some flexibility in choosing an element data\npresentation method and the user of these products needs to be aware of the\nmethod or methods being employed. The following are examples of possible\nimplementations.\nA. WMO Block and Station Number: The data description block would show\ntwo element mnemonics, one for WMO Block Number (BLK) and one for WMO Station\nNumber (STN). These data could be presented in the data block as 2- and 3-byte\nASCII characters or as 1- and 2-byte numeric characters. The user can determine\nthe method of presentation by testing on the \"Number of Bytes per Element\" -\nbyte in the description block.\nB. Present Weather: The data description block would show one of the\nthree present weather mnemonics (WW1, WW2, WW3). The data could be presented in\nthe data block as a numeric code value, following the WMO WW numbering scheme\n(0-99), or as ASCII characters using the accepted meteorological abbreviations\n(e.g., RW, K, etc.) The numeric presentation can be done in one byte in the\ndata block but the ASCII presentation must be done in three bytes. Once again,\nthe user can determine the method of presentation by testing on the \"Number of\nBytes per Element\" - byte in the data description block.\nC. Barometric Characteristic: The data description block would show BC as\nthe el ement mnemonic. Table A2-1 shows that the data would be reported in ASCII\nform as BCO through BC8, corresponding to the nine possible reported code values\n(0 through 8). This ASCII presentation would require three bytes in the data\nblock. The actual code value of 0 through 8 could also be reported as a\none-byte numeric value, scaled with a multiplier of one and additive constant of\n6-1","zero. The USAF has chosen a third method using a special data block data code\nof 160 through 168 (decimal) numeric (see Table A2-2), which also take one byte\nin the data block. However, this code is not considered to be a scaled numeric\nvalue, therefore, the multiplier mantissa and characteristic and additive\nconstant are all zero. This logic can be used to determine the method of\npresentation.\nD. Cloud Amount: The data description block could show CTA (total cloud\namount), L1A - L4A (layer cloud amount), C1A - C3A (layer cloud amount), CLA,\nCMA, CHA (low, middle, and high cloud amount), or SKY (sky cover). The data\ncould be presented in the data block as a three-character ASCII string (CAM,\nCLR, SCT, BKN, OVC, OBS, CAO - CA9). The data could also be presented as a\none-byte numeric value indicating the eighths or tenths of cloud cover or as a\npercent of cover, with units code and scaling factor being the descriminator.\nThe USAF has chosen a third method using a special data block data code of 149\nthrough 159 (decimal) numeric (see Table A2-2), which also takes one byte in the\ndata block. As with barometric characteristic, this USAF code is not considered\nto be a scaled numeric value, therefore, the multiplier mantissa and\ncharacteristic and additive constant are all zero.\nE. Cloud Type, Past Weather, Ship Direction: The data description block\ncould show CLT, CMT, CHT, CT, C1T, C2T, C3T, L1T - L4T, PWX, SD, or SDD for\nthese elements. The data could be shown in three bytes in the data block as\nASCII characters, as listed in Table A2-1. The USAF has chosen special data\nblock data codes, which take one byte in the data block, for reporting the\nelement value (Table A2-2). As with the other special data block data codes,\nthese codes are not considered to be scaled numeric values so the multiplier\nmantissas and characteristics and additive constants are all zero.\n6.4.1 Formatted Mixed Data. The Formatted Binary Data Description Block,\nOption 2 (Figure 6.3), has been provided to handle the transfer of Profiler and\nProfiler-related data among both Government and non-Government agencies. It\npermits mixed numerical representations (two's complement integer, ASCII, IEEE\nfloating point, etc.) and array lengths within the same data block. This means\nthat a data producer can send header information, data elements, and data\narrays; use any defined data representation; and send data in any order.\n6-2","FF :\nLENGTH (I)\n003\n020\nCHARACTER 1\nCHARACTER 2\nStation Call Letters\nCHARACTER 3\nCHARACTER 4\n(ICAO)\nWMO BLOCK NUMBER (I)\nSTATION NUMBER (I)\nLATITUDE I\nLONGITUDE I\nCHECKSUM\nFigure 6.1\nFormatted Binary Product Definition Block\nMode 3, Submode 20\nNOTES: Figure 6.1: Formatted Binary Product Definition Block;\nMode 3, Submode 20\nStation Call Letters: The International Civil Aviation Organization (ICAO)\n1.\nidentification of the originator station.\n2. WMO BLOCK NUMBER: A two digit identifier of a section of the earth based on\na system developed by the World Meteorological Organization (WMO).\n3. STATION NUMBER: A three digit station identification within the region\nidentified by the WMO BLOCK NUMBER.\n4. LATITUDE, LONGITUDE I: Latitude and Longitude must be multiplied by .01 to\nget the actual value. Negative latitude indicates South, negative longitude\nindicates East.\n6-3","FF\nLENGTH (I)\n003\n021\nNUMBER OF ELEMENTS : # OF BYTES/SECTION\nNUMBER OF SECTIONS\nCHARACTER 1\nCHARACTER 2\nElement\nMnemonic\nCHARACTER 3\nCHARACTER 4\nSTART BYTE\n# BYTES/ELEMENT\nUNUSED (ZEROES)\nUNITS CODE\nMULT. MANTISSA\nMULT. CHAR.\nADDITIVE CONSTANT\nCHARACTER 1\nRepeated bytes\nADDITIVE CONSTANT\nCHECKSUM\nFigure 6.2\nFormatted Binary Data Description Block, Option 1\nMode 3, Submode 21\n6-4","NOTES: Figure 6.2: Formatted Binary Data Description Block, Option 1; Mode 3,\nSubmode 21. This block is also used for unpacked gridded products.\n1. NUMBER OF ELEMENTS: The number of elements contained in each section of\nthe data block. This field indicates the number of 12 byte repeating sections\nin the data description block.\n2. NUMBER OF BYTES/SECTION: Total number of bytes contained in a repeating\nsection. This is the number of bytes that must be skipped to read a given\nelement from each repeating section.\n3.\nNUMBER OF SECTIONS: The total number of repeating sections in the data\nblock.\n4. ELEMENT MNEMONIC: A character set that identifies the element being\ndescribed. Tables A2-1 and A2-2 (Annex A) contain the mnemonics lists.\n5. START BYTE: The byte number in the data block where the first occurrence\nof the element can be found. Succeeding occurrences of the element can be found\nby successively adding the number of bytes per section to the start byte number.\n6. NUMBER OF BYTES/ELEMENT: The number of bytes in the data block occupied by\nthe element.\n7. UNITS CODE: A code specifying the units of the data elements. The list of\nunits codes is found in Table C2-6 (Annex c)\n8.\nMULTIPLIER MANTISSA: Integer constant to be multiplied by the element\nvalue to obtain the actual value of the element. Used in conjunction with the\nmultiplier characteristic.\n9. MULTIPLIER CHARACTERISTIC: Exponent of 10 to be used with the multiplier\nmantissa to obtain the true value of the element.\n10. ADDITIVE CONSTANT: Integer constant to be added to the element value to\nobtain the true value of the element.\n11. The ninth through twentieth bytes are repeated for each element in the data\ntype being transmitted. These 12 bytes may be repeated for up to 256 para-\nmeters (0-255). The actual number of 12 byte fields required depends on the\ndata being transmitted.\n12. The actual value of the element is calculated as shown below:\nMult. Char.\nActual Value = Element Value * Mult. Mantissa* 10\n+ Additive Constant\n6-5","FF\nLENGTH (I)\n3\n:\n022\nNUMBER OF ELEMENT SETS\nNUMBER OF BYTES/SECTION\nNUMBER OF SECTIONS\nCHARACTER 1\nCHARACTER 2\nELEMENT SET MNEMONIC\nCHARACTER 3\nCHARACTER 4\nSTART BYTE\nNUMBER OF BYTES/ELEMENT SET\nNUMBER OF BYTES/ELEMENT\nDATA REP. CODE\n:\nUNITS CODE\nMULT. MANTISSA\n:\nMULT. CHAR.\nADDITIVE CONSTANT\nCHARACTER 1\nRepeated descriptor bytes\nADDITIVE CONSTANT\nCHECKSUM\n+\n+\nFigure 6.3\nFormatted Binary Data Description Block, Option 2\nMode 3, Submode 22\n6-6","NOTES: Figure 6.3: Formatted Binary Data Description Block, Option 2; Mode 3,\nSubmode 22. This block is used for formatted mixed data such as two's\ncomplement integer, ASCII, IEEE floating point, etc. and array lengths.\n1. NUMBER OF ELEMENT SETS: The number of element sets (an element set is\neither one element or an array of elements) contained in each repeating section\nof the data block(s). This field indicates the number of 16 byte repeating\ndescriptors in the data description block.\n2. NUMBER OF BYTES/SECTION: Total number of bytes contained in a repeating\nsection. This is the number of bytes that must be skipped to read the first\nelement of a given element set from each repeating section.\n3. NUMBER OF SECTIONS: The total number of repeating sections in the data\nblock(s).\nThe remaining parts of the data description block are the repeating descriptors\ndescribed in note 1.\n4.\nELEMENT SET MNEMONIC: A four-character set that identifies the element set\nbeing described. Tables A2-1 and A2-2 of the reference contain these mnemonics.\n5. START BYTE: The byte number in the data block where the first occurrence\nof the element set can be found. Succeeding occurrences of the element set can\nbe found by successively adding the number of bytes per section to the start\nbyte number.\n6. NUMBER OF BYTES/ELEMENT SET: The number of bytes in the data block\noccupied by the element set.\n7. NUMBER OF BYTES/ELEMENT: The number of bytes in the data block occupied\nby\neach element of the set. (If this is equal to the NUMBER OF BYTES/ELEMENT SET,\nthen this element is not an array. )\n8. DATA REPRESENTATION CODE: A code specifying the representation type of the\nelement. Table C2-7 (ANNEX C) lists the codes. Examples of data representation\nare two's complement integer, Floating point, or ASCII.\n9. UNITS CODE: A code specifying the units of the data elements. Table C2-6\n(ANNEX C) contains these codes.\n10. MULTIPLIER MANTISSA: Integer constant to be multiplied by the element\nvalue obtain the actual value of the element. Used in conjunction with the\nmultiplier characteristic.\n11. MULTIPLIER CHARACTERISTIC: Exponent of 10 to be used with the multiplier\nmantissa to obtain the true value of the element.\n12. ADDITIVE CONSTANT: Integer constant to be added to the element value to\nobtain the true value of the element.\n6-7","FF :\nLENGTH (I)\n003\n001\nDATA SECTION 1\nDATA SECTION 2\nDATA SECTION 3\nDATA SECTION n\nCHECKSUM\nFigure 6.4\nFormatted Binary Data Block\nMode 3, Submode 1\nNOTE: This block is also used for unpacked gridded data.\n6-8","7.0 VECTOR GRAPHIC BLOCKS\n7.1 Product Definition Blocks. One of the following product definition\nblocks (the Vector Graphic Product Definition Block or the Define Graphics\nParameters Product Definition Block) must be used to define the product.\nA\nproduct data set contains only one of the Product Definition blocks.\n7.1.1 Vector Graphic Product Definition Block. The specific format and\ninformation content shall be as shown in Figure 7.1. Most vector graphic data\nis transmitted so that each point can be registered to its true earth location\n(latitude/longitude) or to Cartesian coordinates. Specifically, the earth\nlocatable vector graphic data applies to the vector lines (isopleths, geo-\npolitical lines and latitude/longitude lines), data plots, and wind barbs, and\nline labels. Other data to further describe the product, such as legends, are\nregistered with respect to product locations (e.g., upper left hand corner)\nrather than to earth locations. This data may include line labels and legends.\n7.1.1.1 Product Area. The AREA CODE and SCALE elements define the area of\nthe product to the display device. The AREA CODE shall specify the number and\nlocation of the point(s) used to define the product area. When one point is\nused, the SCALE must also be used for area definition.\n7.1.1.2 Registration. Registration to the display device may be accom-\nplished by applying the reference latitudes and longitudes in accordance with\nthe AREA CODE specification. Registration of the product to background\ninformation is accomplished through the PI set. If PI=0, the appropriate\nbackground data is sent with the product or the product is not geographical in\nnature. Otherwise background data resident in the receiving system is to be\nused.\n7.1.2 Define Graphics Parameters Product Definition Block. This block\nshall be formatted as shown in Figure 7.2. This product definition block is\nsimilar to the Vector Graphic Product Definition Block except that it contains\nadditional information to allow contouring at the user site. Normalized values\nof a contour are provided to allow calculation of successive contours.\n7.2 Data Description Blocks. No data description blocks are currently\nused for the Vector Graphic products.\n7.3 Data Blocks. The Vector Graphic data blocks shall be formatted as\nshown in Figures 7.3 through 7.10 defined in the following sections.\n7.3.1 Absolute Vectors Block. This block shall be formatted as shown in\nFigure 7.3. Each block shall contain coordinates of the vector end points that\ndefine one line on the product. If the length of the line requires more vectors\nthan can be contained in a single block, additional blocks shall be used with\nthe starting M/N coordinates set to the last M/N coordinate of the proceeding\nblock. One or more data blocks may follow, as required to define all lines on\nthe product.\n7.3.2 Relative Vectors Block. This block shall be formatted as shown in\nFigure 7.4. Each block shall contain vector pairs (with coordinates as speci-\nfied by the coordinate flag in the product definition block) that define one\n7-1","line on the product. This block is used to transmit lines consisting of only\nshort vectors, i.e., vectors for which the vector deltas can be put in one byte.\nIf the length of the line requires more vectors than can be contained in a\nsingle block, additional blocks shall be used with the starting M/N coordinates\nset to the last M/N coordinate of the proceeding block. One or more data blocks\nmay follow as required, to define all lines on the product.\n7.3.3 \"Calcomp Pen Command\" (CPC) Vectors Block. This block shall be\nformatted as shown in Figure 7.5. This block contains a series of three bit\ndirection vectors of unit length. If the length of the line requires more\nvectors than can be contained in a single block, additional blocks shall be used\nwith the starting M/N coordinates set to the last M/N coordinate of the proceed-\ning block. One or more data blocks may follow as required, to define all lines\non the product.\n7.3.4 Variable Exception Vectors (VEV) Block. This block shall\nbe\nformatted as shown in Figure 7.6. The format provides a convenient method of\npacking vector graphic lines to conserve transmission time. Each vector graphic\nline is defined by a series of vectors whose lengths are given by the Increment\nLength (IL) and whose directions are given by changes dictated by the VEV data\nbits. The direction of the first increment in the vector graphic line is given\nby the initial direction (IDV) element. Starting with the most significant bit\nin the first byte of the VEV data bits, each bit represents either a trend\n(continue in the same direction) or an exception movement (change in direction)\nalong successive vector increments. If the bit is zero (0), the movement is\nalong the direction last established as the current trend direction. Initially,\nthis is the direction defined by the initial direction element. For bit zero\n(0) and all other even numbered bits, if the bit is one, then the movement\nis\nturned counterclockwise by a 45 degree increment and the new direction is\nestablished as the current trend direction. For bit one (1), and all successive\nodd-numbered bits, if the bit is one (1), then movement is turned clockwise 45\ndegrees and established as the new trend direction. This cycle continues until\nthe bit count indicated by the VEV bit count element is exhausted.\n7.3.5 Long/Short Relative Vectors Block. This block shall be formatted as\nshown in Figure 7.7. Each block shall contain vector pairs that define one line\non the product. If the length of the line requires more vectors than can be\ncontained in a single block, additional blocks shall be used with the M and N\ncoordinate set to the end point of the last vector in the proceeding block. One\nor more additional blocks may follow, as required, to define all lines on the\nproduct. This block is used to transmit lines consisting of both vectors that\ncan be put into one byte and vectors that require 16 bits.\n7.3.6 Point-Slope Vectors Block. This block shall be formatted as shown\nin Figure 7.8. This block provides the minimum amount of information to draw a\nstraight line. The information for only one line is sent with each block. One\nor more additional blocks may follow to define more lines on a product.\n7.3.7 Wind Barbs Vectors Block. This block shall be formatted as shown in\nFigure 7.9. The block is used to transmit wind direction and speed in symbolic\nform. Multiple wind barbs may be transmitted in a single block. Additional\nblocks may be used, as required, to transmit all wind barbs associated with a\nproduct.\n7-2","7.3.8 Vector (Arrow) Plot Block. This block shall be formatted as shown\nin Figure 7.10. This block contains a code for drawing arrows and numerical\nvalues at point locations on a product. One or more data blocks may follow to\ndefine all arrows on a product.\n7-3","LENGTH (I)\nFF :\n004\n020\nCOORDINATE FLAG\nPI SET\nSCALE FACTOR\nLABEL CODE\nAREA CODE\nREFERENCE M COORDINATE\nREFERENCE N COORDINATE\nREFERENCE M COORDINATE\nREFERENCE N COORDINATE\nREFERENCE M COORDINATE\nREFERENCE N COORDINATE\nDAY\nMONTH\nValid Time\nMINUTE\nHOUR\nEnd of Valid\nDAY\nMONTH\nPeriod\nHOUR\nMINUTE\nCHECKSUM\nFigure 7.1\nVector Graphic Product Definition Block\nMode 4, Submode 20","NOTES: Figure 7.1: Vector Graphic Product Definition Block; Mode 4, Submode 20\n1. PI SET: The PI SET defines the background projection on which the product\nis valid. The codes are shown in Table C2-2. If a product is not associated\nwith a background field, PI SET will be zero filled.\n2. COORDINATE FLAG: Coordinate System Indicator as follows:\nFlag\nM =\nN =\n0\nLatitude\nLongitude (Earth surface grid in latitude and\nlongitude coordinates)\n1\nI\nJ\n(Cartesian coordinates of the earth's\nsurface)\n2\nX\nY\n(Pixel coordinates of the product\nbackground projection)\n3. SCALE FACTOR: The Scale Factor is the real world map scale in millions.\nThe first byte contains the integer part and the second byte contains the\nfraction.\n4. AREA CODE: The AREA CODE is an integer code that defines the relative pro-\nduct reference point( (s) and scheme used to define the geographical area and\nproduct orientation. The currently defined codes are:\n11 - One (1) reference point is used to define the upper left corner of\nthe product.\n12 - One (1) reference point is used to define the lower left corner of\nthe product.\n13 - One (1) reference point is used to define the center of the product.\n21 - Two (2) reference points are used to define the upper left and upper\nright corners of the product.\n22 - Two (2) reference points are used to define the lower left and upper\nright corners of the product.\n23 - Two (2) reference points are used to define the upper left and center\nof the product.\n24 - Two (2) reference points are used. The first reference point gives\nthe coordinates of the lower left corner of the product in units of the\ngrid from which it was extracted. The second set of reference coordinates\nwill give the maximum horizontal and maximum vertical size of the product\nin pixels (M maximum and N maximum).\n25 - Same as code 24 except the reference point is located at the center\nof the product.\n7-5","33 - Three (3) reference points are used to define the upper left, upper\nright, and lower right corners of the product.\n34 - Two (2) reference points are used to define the lower left and upper\nright corners, respectively, of the product with respect to orientation the\nproduct would have if viewed on a display screen, and the third reference\npoint defines the upper right conrner of the logical display device.\nWhen only one reference point is required, this block is shortened by two byte\npairs; when two reference points are required the block is shortened by one byte\npair.\n5. LABEL CODE: If LABEL CODE = 0, the label to be used with the product is not\na standard label and the label will be sent in an alphanumeric block. For\ninteragency use this field will be zero. If a standard label is to be used, the\nLABEL CODE will contain a code for that label. Label codes are user definable\nand unique to each system.\n6. Reference Coordinates: The Reference Coordinates uniquely define the\nboundary and orientation of the product. M and N are determined by the\nCOORDINATE FLAG above. If given in latitude/longitude, values will be in\nhundredths of a degree. If given in I/J or X/Y coordinates, values will be\nintegers. These reference points will be in the order specified by the area\ncode (e.g., for area code 33, the first point defines the upper left corner, the\nsecond the upper right corner and the third the lower right corner.)\n7. Valid Time: The Valid Time is the time for which the product is valid. For\nanalysis products, the valid time will be the time the data used to generate the\nproduct was observed. For forecast products, the valid time will be either the\ntime in the future for which the forecast is valid or the start of the time\nperiod for which the forecast is valid. The End of Valid Period time indicates\nthe termination time of the valid period. If the day element of the End of\nValid Period is zero, the product is valid only at the valid time. If not, the\nproduct is valid for the period given.\n7-6","FF :\nLENGTH (I)\n004\n030\nPI SET\nCOORDINATE FLAG\nSCALE FACTOR\nLONGITUDE X (HUNDREDTHS OF DEGREES)\nCONTOUR INTERVAL (I)\nCONTOUR INTERVAL (FRACTION)\nCONTOUR ORIGIN (I)\nCONTOUR ORIGIN (FRACTION)\nM MAXIMUM (I)\nN MAXIMUM (I)\nM CENTER\nN CENTER\nUNITS CODE\nNCHAR (TITLE)\nCHARACTER 1\nCHARACTER 2\nLAST CHARACTER\nCHECKSUM\nFigure 7.2\nDefine Graphics Parameters Product Definition Block\nMode 4, Submode 30\n7-7","NOTES: Figure 7.2: Define Graphics Parameters Product Definition Block; Mode\n4, Submode 30\n1. PI SET: The PI SET defines the background projection on which the product\nis valid. Currently defined codes are shown in Table C2-2.\nCOORDINATE FLAG: Coordinate System Indicator as follows:\n2.\nN =\nFlag\nM =\n(An earth surface grid in latitude and\nLongitude\n0\nLatitude\nlongitude coordinates.)\n(Cartesian coordinates of the earth's\n1\nI\nJ\nsurface)\n(Pixel coordinates of the product\nX\nY\n2\nbackground projection)\n3. SCALE FACTOR: The Scale Factor is the real world map scale in millions.\nThe first byte contains the integer part and the second byte contains the\nfraction.\n4. LONGITUDE X : This is the longitude of the meridian perpendicular to the\nbase of the product and extending from the base of the product to the pole.\nLongitude X may be outside of the product boundaries. Table C2-2 shows the\nLongitude X for the defined PI Sets (map projection). Longitude X is given in\nhundredths of degrees and must therefore be multiplied by .01 to obtain the true\nvalue.\n5. CONTOUR INTERVAL and CONTOUR ORIGIN: The CONTOUR INTERVAL (CI) and CONTOUR\nORIGIN (CO) are used to relate the Band Index (BI) value of the first contour in\nthe product to the value of other contours in the product as follows:\nValue = BI * CI + CO\nThe BI is sent in the Data Block.\n6. M,N MAXIMUM: The maximum horizontal and vertical size of the product. The\ntype of coordinates are determined by the COORDINATE FLAG above.\n7. M,N CENTER: The coordinates of the center of the product in units of the\ngrid from which the product was originally extracted.\n8. UNITS CODE: A code specifying the units of the contours in the product.\nThe list of units is found in Table C2-6.\n9. NCHAR: The number of characters in the product title.\n10. CHARACTERS 1-n: The ASCII characters that make up the product title.\n7-8","FF :\nLENGTH (I)\n004\n001\nM COORDINATE\nN COORDINATE\nM COORDINATE (1)\nB\nN COORDINATE (1)\nM COORDINATE (2)\nB\nN COORDINATE (2)\nM COORDINATE (n)\nB\nN COORDINATE (n)\nCHECKSUM\nFigure 7.3\nAbsolute Vectors Block\nMode 4, Submode 1\nNOTES: Figure 7.3: Absolute Vectors Block; Mode 4, Submode 1\n1. M,N COORDINATE:\nFirst set of coordinates of the line. M and N are\ndetermined by the COORDINATE FLAG in the Product Definition Block.\n2.\nM,N COORDINATES (n): Successive coordinates which form the line.\n3. B = Blanking Flag: If B=0, pen is up (beam off), and a new line starts. If\nB=1, pen is down (beam on), , and a line is drawn between the coordinate pairs.\n7-9","LENGTH (I)\n:\nFF\n004\n002\nM COORDINATE\nN COORDINATE\nDELTA N(1)\nDELTA M(1)\nDELTA N(2)\nDELTA M(2)\nDELTA N(3)\nDELTA M(3)\nDELTA N(n)\nDELTA M(n)\nCHECKSUM\nFigure 7.4\nRelative Vectors Block\nMode 4, Submode 2\nNOTES: Figure 7.4: Relative Vectors Block; Mode 4, Submode 2\n1. M,N COORDINATE: Defines vector string starting point. M and N are deter-\nmined by the COORDINATE FLAG in the Product Definition Block.\n2. DELTA M, N Values: Successive values are added algebraically to the last\ncomputed M, N coordinate position to produce a series of vectors defining a\nline. The positive direction for M values is to the right, negative to the\nleft. The positive direction for N values is up, negative is down. Negative\nvalues are entered in 2's complement notation.\n7-10","FF :\nLENGTH (I)\n004\n003\nM COORDINATE\nN COORDINATE\nVECTOR COUNT (I)\nCPC VECTORS\nCHECKSUM\nFigure 7.5\nCPC Vectors Block\nMode 4, Submode 3\n7-11","NOTES: Figure 7.5: CPC Vectors Block; Mode 4, Submode 3\n1. M,N COORDINATE: Defines vector string starting point. M and N are\ndetermined by the COORDINATE FLAG in the Product Definition Block.\n2. VECTOR COUNT: Number of vectors following.\nSuccessive fields containing values defining the vector\n3. CPC Vectors:\ndirection corresponding to the sketch below. The field width is variable\ndepending on the Define Datawidth/Fieldwidth Block. The data width = 3. If\nthere is no Datawidth/Fieldwidth Block, the default bit configuration is five 3\nbit vectors, right justified in one byte pair, with the left bit equal to 0.\nTo\nend on a byte pair boundary the last two bytes are zero filled if necessary.\n0\n/1\n6\n2\n3\n4\n4. The vector length is one pixel.\n7-12","FF :\nLENGTH (I)\n004\n004\nM COORDINATE\nN COORDINATE\nBAND INDEX\nIL\n:\nIDV\nVEV BIT COUNT (I)\nVEV BITS\nCHECKSUM\nFigure 7.6\nVariable Exception Vectors (VEV) Block\nMode 4, Submode 4\n7-13","NOTES: Figure 7.6: Variable Exception Vectors (VEV) Block; Mode 4, Submode 4\nDefines vector string starting point. M and N are\n1. M,N COORDINATE:\ndetermined by the COORDINATE FLAG in the Product Definition Block.\nBAND INDEX: The BAND INDEX (BI) is the normalized value of a contour or\n2.\nline, where BI = (Value - Origin)/Interval If BI is not used this field will\ncontain 377 octal (all one bits)\n3. IL = Increment Length: IL is the indicator for the incremental vector length\n(e.g., , 1=1 pixel, 2=2, 3=3,\n, 7=7)\n4. IDV = Initial Direction Vector: IDV values are 0 through 7 as represented in\nthe sketch below:\nDirection vector definition:\n7\n0\n1\n+\nX\nX\nX\nX\nX\nX\nX\nX\nX\nX\nX\nN 6\n2\nX\nX\nX\nX\nX\nX\nX\nX\nX\nX\nX\nX\nX\n+\n4\n5\n3\nM\n+\nVEV BIT COUNT: The number of data bits following.\n5.\nVEV BITS: The string of bits determining the VEV vectors. If this bit\n6.\nstring does not fill the last byte pair, the remaining bits are set to zero to\nend on a byte pair boundary.\n7-14","FF :\nLENGTH (I)\n004\n005\nM COORDINATE\nN COORDINATE\n1|\nDELTA M\nB|\nDELTA N\nOR\nOX\nX\nDELTA M\nOX\nB\nDELTA N\nCHECKSUM\nFigure 7.7\nLong/Short Relative Vectors Block\nMode 4, Submode 5\n7-15","NOTES: Figure 7.7: Long/Short Relative Vectors Block; Mode 4, Submode 5\n1. M, N COORDINATE: Defines vector string starting points. M and N are\ndetermined by the COORDINATE FLAG in the Product Definition Block.\n2. Left-most Bit: If the left-most bit = 1, the DELTA M and N are short\n(contained in one byte) vector values. If the left-most bit = 0, the DELTA M\nand N are long (each contained in two bytes) vector values.\n3. B = Blanking Flag: If B=1, no line is drawn between coordinate pairs. If\nB=0, the line is drawn.\n4. X: This bit not used.\n5. DELTA M, N : Each successive delta value is added algebraically to the last\ncomputed M, N coordinate position to produce a series of vectors defining a\nline. The positive direction for M values is to the right, negative is to the\nleft. The positive direction for N values is up, negative is down. Negative\nvalues are entered in two's complement notation.\n7-16","FF\n:\nLENGTH (I)\n004\n006\nM COORDINATE\nN COORDINATE\nVECTOR LENGTH\nSLOPE\nOCT\nCHECKSUM\nFigure 7.8\nPoint-Slope Vectors Block\nMode 4, Submode 6\nNOTES: Figure 7.8: Point-Slope Vectors Block; Mode 4, Submode 6\n1.\nM,N COORDINATE: Defines vector string starting point. M and N are defined\nby the COORDINATE FLAG in the Product Definition Block.\n2. VECTOR LENGTH: VECTOR LENGTH is the larger of the absolute values of the\ndelta M and delta N differences for the two points between which the line is to\nbe drawn.\n3. SLOPE: SLOPE is the fractional value of the ratio (shorter delta)/(longer\ndelta). This value is multiplied by 2**12.\n4. OCT: OCT is a four bit field and contains the value for an octant defined\nin the following sketch:\n\\7|0/\n6\\|/1\n5/|\\2\n/4:31\n7-17","FF\n:\nLENGTH (I)\n004\n007\nSHAFT LENGTH\nUNUSED\nM COORDINATE(1)\nN COORDINATE(1)\nDIRECTION H |5kt\n10 kt :\n50 kt\nM COORDINATE(2)\nN COORDINATE(2)\nDIRECTION H |5kt\n10 kt\n50 kt\nM COORDINATE(n)\nN COORDINATE(n)\nDIRECTION H |5kt 10 kt : 50 kt\nCHECKSUM\nFigure 7.9\nWind Barbs Vectors Block\nMode 4, Submode 7\n7-18","NOTES: Figure 7.9: Wind Barbs Vectors Block; Mode 4, Submode 7\n1. SHAFT LENGTH: Number of pixels for the shaft line (from base to first\nbarb).\n2. M,N COORDINATE: Position of the base of the shaft. M and N are determined\nby the COORDINATE FLAG in the Product Definition Block.\n3. DIRECTION: A six bit field containing an integer number in tens of degrees.\nIt specifies the screen direction from which the wind is blowing. (Top of\ndisplay screen is 0°.)\n4. H = HEMISPHERE: A one bit field where H=O represents the Northern\nHemisphere. H=1 represents the Southern Hemisphere.\n5. 5Kt: A one bit field indicating the number of five knot flags.\n6. 10Kt: A four bit field containg the number of ten knot flags.\n7. 50Kt: A four bit field containing the number of fifty knot flags.\n7-19","FF\nLENGTH (I)\n004\n010\nM COORDINATE(1)\nN COORDINATE(1)\nCODE\nDIRECTION\nARROW LENGTH\nVALUE\nM COORDINATE(2)\nN COORDINATE(2)\nCODE\nDIRECTION\nARROW LENGTH\nVALUE\nM COORDINATE(n)\nN COORDINATE (n)\nCODE\nDIRECTION\nARROW LENGTH\nVALUE\nCHECKSUM\nFigure 7.10\nVector (Arrow) Plot Block\nMode 4, Submode 10\n7-20","NOTES: Figure 7.10: Vector (Arrow) Plot Block; Mode 4, Submode 10\nM,N COORDINATE: The coordinate where the arrow and/or value is to be\n1.\ncentered. M and N are determined by the COORDINATE FLAG in the Product\nDefinition Block.\n2. CODE: An integer value defining the type of information to be plotted. The\ncurrently defined codes are:\nCode\nArrow through point M,1 N\n1\nArrow from point M,N\n2\n>--o\n3\nArrow to point M,1 N\nArrow with value plotted at M,1 N\n4\n21\nArrow from M, N with VALUE plotted left of M,N\n5\n22o\nArrow to M, N with VALUE plotted to right of M, N\n6\n041\nVector of length (in pixels)\n7\n>\nThe arrow direction in tens of degrees, relative to display\n3. DIRECTION:\ndevice screen. (Top of screen is 0°.)\n4. Arrow Length: The length of the arrow in pixels for CODEs 1 through 6.\n5. VALUE: An integer value to be plotted for CODES 4, 5 and 6. If CODE = 7,\nthe VALUE contains the length of the vector in pixels.\n7-21","8.0 ALPHANUMERIC BLOCKS\n8.1 Product Definition Block. This block shall be a variable length block\nincluding the LENGTH and CHECKSUM when used. The format shall be as shown in\nFigure 8.1. This block is optional. An example of an application would be to\nprovide additional routing information for alphanumeric messages.\n8.2 Data Description Block. This block is not currently used for alpha-\nnumeric data.\n8.3 Data Blocks. The Alphanumeric data blocks shall be formatted as shown\nin Figures 8.2 through 8.5. These blocks are defined in the following\nparagraphs.\n8.3.1 Alphanumeric Characters Block. This block shall be formatted as\nshown in Figure 8.2. This block is used to transmit textual information to be\nplaced on displayed products (e.g., graphics products). Each block\nshall\ntransmit one complete string of ASCII characters, including control characters.\nThis block will normally be used to transmit nonstandard product labels/legends\nor variable information to be placed in a standard label/legend.\n8.3.2 Plot Data Block. This block shall be formatted as shown in Figure\n8.3. This block is used to transmit alphanumeric characters to be displayed at\na specific location on a product in a specified format. Each block may be used\nto transmit labels for one or more lines on the product. It may be used to\ntransmit weather symbols (such as thunderstorm symbols) that are to be displayed\nat a specified location on the product. The block may transmit any number of\nsymbols as long as they are all to be displayed in the same size and color. The\ndisplay format to be used is specified by a plot code. The Plot Process Code\noptions are listed in Table C2-3.\n8.3.3 Wind Barbs Data Block. This block shall be formatted as shown in\nFigure 8.4. The block is used to transmit wind direction and speed observations\nor forecasts to place a wind barb symbol at the specified location on the\nproduct. Multiple wind barbs may be transmitted in a single block. Additional\nblocks may be used, as required, to transmit all wind barbs associated with a\nproduct.\n8.3.4 Alphanumeric Data Block. This block shall be formatted as shown in\nFigure 8.5. The data field shall contain an even number of ASCII characters\nwhich comprise all or part of the message text. All man-readable messages not\nintended for display shall use this block. The block follows the conventions\nfor non-graphic data outlined in Section 2.2.3.2.\n8-1","LENGTH (I)\nFF\n:\n005\n020\nCHARACTER 1\nCHARACTER 2\nCHARACTER 3\nCHARACTER 4\nCHARACTER 5\nCHARACTER 6\nLAST CHARACTER\nCHECKSUM\nFigure 8.1\nAlphanumeric Product Definition Block\nMode 5, Submode 20\nNOTES: Figure 8.1: Alphanumeric Product Definition Block; Mode 5, Submode 20.\n1.\nCHARACTERS: The CHARACTER fields may be used to define additional\ninformation concerning the alphanumeric blocks. The block contains an even\nnumber of ASCII characters. This block follows the conventions for non-graphic\ndata outlined in Section 2.2.3.2.\n8-2","FF\nLENGTH (I)\n005\n001\nM COORDINATE\nN COORDINATE\nDELTA M\nDELTA N\nB| R| CHAR. SIZE\nCHARACTER 1\nCHARACTER 2\nCHARACTER 3\nCHARACTER 4\nCHARACTER 5\nCHARACTER n-1\nCHARACTER n\nCHECKSUM\nFigure 8.2\nAlphanumeric Characters Block\nMode 5, Submode 1","NOTES: Figure 8.2: Alphanumeric Characters Block; Mode 5, Submode 1\n1. M,N COORDINATE: The M and N coordinate element identifies of the starting\nposition of the textual string. It references the lower left corner of the\nfirst character in the string. M and N are determined by the COORDINATE FLAG in\nthe Product Definition Block.\n2. DELTA M, N: The DELTA M and DELTA N identify the start point of the first\ncharacter in the string at some desired distance from the M and N coordinate\nelement. The distance remains fixed despite whatever zoom value is used.\n3. B = Block Mode: The Block Mode is the indicator for the blanking area\ncovered by a character. If B = 1, a rectrangular display area is cleared\nbeneath the standard generated character. If B = 0, the character is displayed\nnormally unless R = 1.\n4. R = Reverse Block Mode: The Reverse Block Mode is an indicator for reverse\nvideo (negative image). R = 0 is for normal image. R = 1 is the same as B = 1,\nexcept the display polarity is reversed.\n5. CHAR SIZE: Defines the height/width of a character relative to the font\nsize. Zero indicates standard font size of the display device. If the element\nis non-zero, it represents a multiplicative factor applied to the standard\ncharacter size, e.g., 0 = 5 X 7, 1 = 10 X 14, 2 = 15 X 21, etc.\n8-4","FF :\nLENGTH (I)\n005\n002\nB| R\nCHAR SIZE\nPLOT PROCESS CODE\nM COORDINATE (1)\nN COORDINATE (1)\nCHARACTER 1\nCHARACTER 2\nCHARACTER 4\nCHARACTER 3\nCHARACTER n-1\nCHARACTER n\nM COORDINATE (m)\nN COORDINATE (m)\nCHARACTER 1\nCHARACTER 2\nCHARACTER n-1\nCHARACTER n\nCHECKSUM\nFigure 8.3\nPlot Data Block\nMode 5, Submode 2\n8-5","NOTES: Figure 8.3: Plot Data Block; Mode 5, Submode 2\n1. B = Block Mode: The Block Mode is the indicator for the blanking area\ncovered by a character. If B = 1, a rectangular display area is cleared beneath\nthe standard generated character. If B = 0, the character is displayed normally\nunless R = 1.\n2. R = Reverse Block Mode: The Reverse Block Mode is an indicator for reverse\nvideo (negative image). R = 0 is for normal image. R = 1 is the same as B = 1,\nexcept the display polarity is reversed.\n3. CHAR SIZE: Defines the height/width of a character relative to the font\nsize. Zero indicates standard font size of the display device. If the element\nis nonzero, it represents a multiplicative factor applied to the standard\ncharacter size, e.g., 0 = 5 X 7, 1 = 10 X 14, 2 = 15 X 21, etc.\n4. PLOT PROCESS CODE: This octal code specifies the processing required to\ninterpret and display the characters 1 through n contained in the block The\nPLOT PROCESS CODES are found in Table C2-3.\n5. M, N COORDINATE: Specifies the geographical point about which the data is\nto be plotted. M and N are determined by the coordinate flag in the Product\nDefinition Block.\n6.\nCharacters\n1\nthrough N: The ASCII character string representing the\nalphanumeric characters or weather symbols as defined by the Plot Process Code.\n8-6","FF\nLENGTH (I)\n005\n003\nSHAFT LENGTH\nBLANKING FLAG\nM COORDINATE (1)\nN COORDINATE (1)\nDIRECTION (1)\nSPEED (1)\nGUST (1)\nHEMISPHERE (1)\nM COORDINATE (n)\nN COORDINATE (n)\nDIRECTION (n)\nSPEED (n)\nGUST (n)\nHEMISPHERE (n)\nCHECKSUM\nFigure 8.4\nWind Barbs Data Block\nMode 5, Submode 3\n8-7","NOTES: Figure 8.4: Wind Barbs Data Block; Mode 5, Submode 3\n1. SHAFT LENGTH: The number of pixels for the shaft line (from base to first\nbarb).\n2. BLANKING FLAG: An indicator for blanking the area covered by the wind barb\nfont. If left-most bit is set (i.e., a \"1\") the area is blanked, if the\nleft-most bit is off (i.e., a \"0\") blanking is not done.\n3. M,N COORDINATES: Defines the location of the base of the wind barb shaft.\nM and N are determined by the COORDINATE FLAG in the Product Definition Block.\n4. DIRECTION: An intèger number in whole degrees. It specifies the direction\nfrom which the wind is blowing.\n5. SPEED: An integer number in whole knots.\n6. GUST: An integer number in whole knots.\n7.\nHEMISPHERE: An indicator for Northern or Southern Hemisphere. If the\nright-most bit is set (1), the wind flags go to the left of the shaft (Southern\nHemisphere) as viewed from the head of the shaft. If not set (0), the flags go\nto the right of the shaft (Northern Hemisphere).\n8-8",":\nFF\nLENGTH (I)\n005\n004\nCHARACTER 1\nCHARACTER 2\nCHARACTER 3\nCHARACTER 4\nCHARACTER n-1\nB|\nETB or ETX\nCHECKSUM\nFigure 8.5\nAlphanumeric Data Block\nMode 5, Submode 4\nNOTES: Figure 8.5: Alphanumeric Data Block; Mode 5, Submode 4.\n1. CHARACTERS: The data field is an even number of ASCII characters (both\nalphanumeric and control characters) .\n2. B. If B (high order bit) = 1, this byte contains the last character of the\ndata set. This field is optional.\n3. ETB or ETX: The last byte in the block contains the ASCII control character\nETB if the block is not the final block in the product data set. The last byte\nis ASCII control character ETX if the block is the last block in the Product\nData Set. See Section 2.2.3.2.\n8-9","9.0 RASTER SCAN BLOCKS\n9.1 Product Definition Blocks.\n9.1.1 Satellite Product Definition Block. This block shall be formatted\nas shown in Figure 9. 1. This block shall be used to define all raster scan\nproducts that are in the form of visual imagery, i.e., satellite data as opposed\nto facsimile products.\n9.1.2 Pixel Product Definition Block. This block shall be formatted as\nshown in Figure 9.2. This block shall be used for all non-satellite raster scan\nproducts (such as radar or facsimile). The data may be packed to conserve\ntransmission time. The algorithm used to pack the data shall be indicated by\nthe pack code.\n9.2 Data Description Block . No data description blocks are currently used\nfor raster scan products.\n9.3 Data Block. This Raster Scan Data block shall be formatted as shown\nin Figure 9.3. All raster scan products shall use this format with the XROW,\nYCOL, and RESOLUTION fields set to one (all bits on) if not used. The origin is\n0,0. Pixel data in the data field shall be packed as specified by the pack code\nand arranged as specified by the pack code in the Product Definition block. The\ncurrently defined packing algorithms are described in succeeding sections.\n9.3.1 Block Organization.\n9.3.1.1 AFGWC Packing Scheme. Each data block shall contain a field\ngiving the row and column location of the first pixel in the block and the\nresolution of the data, followed by a data field containing the pixel data.\nSucceeding pixels for the remainder of the scan line proceed as specified by the\nscan code. For multi-bit deep raster scan products, the pixel data shall con-\nsist of a pixel value for each pixel location. For single bit deep raster scan\nproducts, the pixel data shall specify state ( on or off). The pixel data shall\nbe organized in the data field as a continuous string of bits. The number of\nbits per pixel shall be specified by the matrix code, i.e., matrix code 01, 11,\n21, 41 indicate one bit pixels, 04, 14, 24, 44, represent four bit pixels, etc.\n9.3.1.2 National Weather Service Packing Scheme. Products packed in\naccordance with this scheme shall have the XROW, YCOL, and the resolution\nelements zero (0) filled. The data field shall be organized such that the pixel\ndata is given in 8-bit bytes and packed within the bytes as follows:\nBit 0\nand\nThese bits are never used.\nBit 1\n9-1","Bit 2 -\nThese two bits determine the type of data described in the byte.\nand\nBit 3\n00 = Number or consecutive pixels in the line in the ON (white)\nstate.\n01 = Number of consecutive pixels in the OFF (black) state.\n10 = Unpacked pixel data.\n11 = Recorder control character.\nBit 4 - These bits contain the pixel count, unpacked pixel data, or the\ncontrol character's lower half. For pixel count, the bits give the\nnumber of pixels OFF or ON in groups of four pixels, as indicated\nby bits 2 and 3. For unpacked pixel data, they give the state ( ON\nand OFF) of the xt four pixels in the scan line. If the byte\ncontains the end-of-scan (EOS) control character, bits 4 through 7\nare off. If the byte contains the end-of-map (EOM) character,\nbits 4 and 5 are off and bits 6 and 7 are on.\nBit 7\nOne byte of the packed pixel data stream can represent, at most, sixty (4*15)\npixels of all white or all black data (i.e., UU001111 or UU011111). If bits two\nand three are the same in two, and at most three, consecutive bytes (e.g., two\nor three bytes containing UUOO, or two or three bytes containing UUO1), then the\npixel count in the second byte represents multiples of sixteen, and the third,\nif present, represents multiples of sixteen squared. For example:\nUU001010 UU000101 UU000001 = 10 + (5 * 16) + (1 * 256)\n= 346 groups = 1384 white pixels (346*4)\nUU000111 UU010011 UU011100 UU110000 = 7 groups of\nwhite, 3 + (12 * 16) groups of black, and end of scan\n= 28 white pixels, 1780 black pixels and end of scan\nEach block will contain one or more scan lines of the product (or partial\nlines) as required to fill the data block. Each complete scan line will be\nfollowed by an end-of-scan (EOS) sequence (UU110000). If a scan line is not\ncompleted before the last byte of a data block, the scan information will\ncontinue in the next block and the data shall be treated as if it had been in\nthe same block. If an EOS is encountered before the end of a scan line, then\nthe remainder of the scan line is white, and the next byte begins the next scan\nline. The final EOS for the product will be followed by an end-of-map (EOM)\nsequence (UU110011). If the EOM sequence is reached before the end of a data\nblock, the remainder of the block will be filled with EOM sequences and the next\nblock will be the End of Product block.\n9-2","9.3.2 Block Length.\n9.3.2.1 Air Force Global Weather Central (AFGWC) Packing Scheme. Data\nblocks will be of fixed length for a given product as determined by the number\nof pixels required to define one complete scan line of the product. Data block\nlength shall be variable from one product to another depending on the size of\nthe product. For example, one product may be a 512 X 512 bit array and another\nmay be a 1024 X 1024 X 6 array.\n9.3.2.2 National Weather Service Packing Scheme. Data blocks will be of\nfixed length for a given product. For example, NWS pixel products are blocked\ninto 960 byte strings. Each block may contain any number of complete or partial\nscan lines as required to fill the block. Data block length will be variable\nfrom one product to another.\n9-3","LENGTH (I)\nFF :\n006\n020\nPI SET\nGI SET\nSATELLITE ID\nLONGITUDE X\nRESOLUTION CODE\nDATA TYPE\nX MAX\nY MAX\nENHANCE MAX\nENHANCE MIN\nLENGTH (MM)\nENHANCE ID\nX CENTER\nY CENTER\nLATITUDE\nLONGITUDE\nCHARACTER 1\nNCHAR\nCHARACTER 2\nCHARACTER 3\nCHARACTER 4\nCHARACTER 5\nCHARACTER n-1\nCHARACTER n\nCHECKSUM\nFigure 9.1\nSatellite Product Definition Block\nMode 6, Submode 20\n9-4","NOTES: Figure 9.1: Satellite Product Definition Block; Mode 6, Submode 20\n1. PI SET: The PI SET defines the background projection on which the product\nis valid. The currently defined codes are shown in Table C2-2. If a product is\nnot associated with a background, PI SET will be zero (0) filled.\n2. GI SET: The Grid Indicator defines the grid on which the data is valid.\nCurrently defined codes are shown in Table C2-4.\n3. SATELLITE IDENTIFICATION: Two ASCII characters that identify the satellite\nfrom which the product was produced.\nThe first character identifies the agency. Currently assigned values are:\nA - Air Force\nE - European\nI - Indian\nJ - Japan\nN - NOAA\nR - Russian\nS - NASA\nV - Navy\nThe second byte may contain a letter or number to designate a specific\nsatellite.\n4. LONGITUDE X : This is the longitude of the meridian perpendicular to the\nbase of the product and extending from the base of the product to the pole.\nLongitude X may be outside of the product boundaries. Table C2-2 shows the\nLongitude X for the defined PI Sets (map projection) .\n5. RESOLUTION CODE: This element specifies the resolution of the satellite\ndata in the product in tenths of nautical miles, i.e., the resolution must be\nmultiplied by . 1 to obtain the actual value.\n6. DATA TYPE: An integer code that specifies the type of satellite data\ncontained in the product. The currently defined codes are:\n0 = Visual (VIS) only\n1 = Infrared (IR) only\n2 = Alternating lines of IR/VIS both day or both night\n3 = Alternating bytes IR/VIS both day or both night\n4 = Alternating lines of night and day both IR or both VIS\n5 = Alternating bytes of night and day both IR or both VIS\n9-5","7. XMAX and YMAX: The maximum horizontal (XMAX) and vertical (YMAX) size of\nthe product in pixels.\n8. ENHANCE MAX and MIN: The limits of the gray scale referenced by ENHANCE ID.\n9. ENHANCE ID: An enhancement identification which points to a table of gray\nscales or an algorithm. Some values are common (for interagency use-Table C2-5)\nand some are user defined.\n10. LENGTH: Length of each scan line in the product in tens of minutes of arc,\ni.e., length must be multiplied by ten to obtain the actual value.\n11. X, Y CENTER: The coordinates of the center of the product in units of the\ngrid from which the product was extracted.\n12. LATITUDE and LONGITUDE: The latitude and longitude of the center of the\nproduct in hundredths of degree, i.e., latitude and longitude must be multiplied\nby .01 to obtain the actual value.\n13. NCHAR: The number of characters contained in the product title that\nfollows.\n14. CHARACTERS 1-n: The ASCII characters that make up the product title.\n9-6","FF :\nLENGTH (I)\n006\n030\nPI SET\nMATRIX CODE\nSCAN CODE\nPACK CODE\nCHECKSUM\nFigure 9.2\nPixel Product Definition Block\nMode 6, Submode 30\n9-7","NOTES: Figure 9.2: Pixel Product Definition Block; Mode 6, Submode 30\n1. PI SET: The PI SET defines the background projection on which the product\nis valid. The currently defined codes are shown in Table C2-2. If a product is\nnot associated with a background, PI SET will be zero (0) filled.\n2. MATRIX CODE: A code defining the dimensions of the pixel array being sent\nin the product. Currently defined codes are:\n11 - 1024 X 1024 X 1\n01 - 512 X 512 X 1\n12 - 1024 X 1024 X 2\n02 - 512 X 512 X 2\n13 - 1024 X 1024 X 3\n03 - 512 X 512 X 3\n14 - 1024 X 1024 X 4\n04 - 512 X 512 X 4\n15 - 1024 X 1024 X 5\n05 - 512 X 512 X 5\n16 - 1024 X 1024 X 6\n06 - 512 X 512 X 6\n17 - 1024 x 1024 X 7\n07 - 512 X 512 X 7\n20 - 1024 x 1024 X 8\n10 - 512 X 512 X 8\n41 - 4096 X 4096 X 1\n21 - 2048 X 2048 X 1\n42 - 4096 X 4096 X 2\n22 - 2048 X 2048 X 2\n43 - 4096 X 4096 X 3\n23 - 2048 X 2048 X 3\n44 - 4096 x 4096 x 4\n24 - 2048 X 2048 X 4\n45 - 4096 X 4096 X 5\n25 - 2048 X 2048 X 5\n46 - 4096 X 4096 X 6\n26 - 2048 X 2048 X 6\n47 - 4096 X 4096 X 7\n27 - 2048 X 2048 x 7\n50 - 4096 X 4096 X 8\n30 - 2048 X 2048 X 8\n63 - 1728 x n X 1 where n is dependent on the size of the product. In this\ncase the number of data blocks must be counted during processing to determine n.\n0 - X N X 1 where M and N are dependent on the size of the product. In\nthis case, M will be specified by the resolution element in the data block and\nthe number of data blocks must be counted during processing to determine N.\n3. SCAN CODE: Used to indicate the order in which the raster scan pixels are\narranged in the data block. The currently used scan codes are:\n1 - Data are arranged in the data block such that pixels are defined row by\nrow (raster scan) from the upper left corner.\n2 - Data are arranged in the data block such that the pixels are defined row\nby row (bottom up raster scan) from the lower left corner.\n9-8","4. PACK CODE: A code defining the algorithm which was used to pack the\nproduct. Currently defined codes are:\n0 - Pixels are unpacked, i.e., each byte contains one pixel.\n1 - Pixels are packed in accordance with the AFGWC packing scheme. See\nSection 9.3.1.1.\n2 - Pixels are packed as specified by the Define Datawidth/Fieldwidth\nblock. See Mode 1, Submode 5.\n128 - Pixels are packed in . accordance with the National Weather Service\nSee Section 9.3.1.2.\n9-9","LENGTH (I)\nFF :\n006\n001\nXROW\nYCOL\nRESOLUTION\nPIXEL DATA\nCHECKSUM\nFigure 9.3\nRaster Scan Data Block\nMode 6, Submode 1\nNOTES: Figure 9.3: Raster Scan Data Block; Mode 6, Submode 1\n1. XROW and YCOL: The row and column number, within the product, where the\nfirst pixel in the data block is located. For example, 0,0 specifies the first\npixel is in row 0, column 0 while 36,492 specifies the first pixel is in row 36,\ncolumn 492. This location is referenced to the scan direction indicated by the\nscan code, i e., for top down scan sequence, 0,0 specifies the upper left corner\nwhile 36,492 specifies the 36th row from the top and the 492nd column from the\nleft.\n2. RESOLUTION: The number of pixels per scan line.\n3. PIXEL DATA: The value, or state, of each pixel in the scan line.\n9-10","10.0 GRIDDED DATA BLOCKS\n10.1 Product Definition Block. The Gridded Data Product Definition Block\nshall be formatted as shown in Figure 10. 1. Gridded data may be transmitted in\npacked or unpacked format, and as latitude/ longitude or I/J grid data, as\ndetermined by the product originator.\n10.2 Data Description Block. The data description block for unpacked\nGridded Data products shall be in the format shown for Formatted Binary Data\nproducts in Figure 6.2. No data description block is used for packed Gridded\nData products. The following conventions shall apply to the Gridded Data data\ndescription block when used.\n10.2. Length and Arrangement of Block. Each element being transmitted in\nthe data block shall be described in the ninth through twentieth bytes and\nsucceeding twelve byte sections. The sections shall be in the same order as the\nelements appear in the element sets of the data block. The length of the data\ndescription block shall be sufficient to describe one or more elements, as\nrequired by the originator of the product.\n10.3 Data Blocks. Due to the significant differences in formal require-\nments for packed and unpacked Gridded Data products, different data blocks are\nused.\n10.3.1 Unpacked Gridded Data Block. The unpacked Gridded Data data\nblock(s) for both latitude/longitude Gridded Data products and I/J Gridded Data\nproducts shall be formatted as shown for Formatted Binary Data in Figure 6.4.\nThe data field of the block shall be formatted as specified in Section 10.2.1\nThe data field within the data block shall contain element sets aligned\nend-to-end as shown in Figure 6.4.\n10.3.2 Band Index Data Block. This block applies to packed Gridded Data\nproducts. Each data block will be used to transmit all grid points in a product\nfor each parameter (e.g., temperature, pressure). One or more additional data\nblocks may be transmitted sequentially to define all parameters in the product.\nBlocks shall be formatted as shown in Figure 10.2.\n10.3.2.1 Data Unpacking Method. In order to discuss unpacking the data,\nthe method and terms involved in packing the scaled integer grid value must be\ndefined. One constant is chosen and included for each type of data field. This\nconstant is divided into each grid value during the packing process in order to\nreduce the number of least significant digits. Use of this Multiplier Constant\n(termed MC in the explanation) produces a value called the Band Index (BI).\nThus for any given grid point value (GV):\nBI=(GV)/MC\nA first order difference value is then calculated between consecutive Band\nIndex Values:\nDelta BI =\nBI\n- BI\nn+1\nn\n10-1","Note that BI and Delta BI are given in the Gridded Data Product Defini-\n1\n1\ntion Block. Now second order derivatives are computed from the first order\ndifferences:\n2\nDelta\nBI = Delta BI\n- Delta BI\nn+1\nn\n2\nThe data part of the data block consists entirely of Delta BI ,\n2\nDelta BI for a data field with p data points. During packing, the Delta BI\np-2\ncomputed between the last element of each row and the first element of the next\nrow is computed using the next element directly above rather than beginning at\nthe left side of the next row. Therefore, the scanning computation proceeds\n, rows and right-to-left for the 2nd, 4th,\nleft-to-right for the 1st, 3rd,\nrows. Decoding grid point value n, then, is done as:\n2\nGV n = (BI n-1 + Delta BI n-2 + Delta BI n-2 ) * MC\n10.4 Grid Conventions. The three key agencies capable of producing\ngridded products in accordance with these formats are National Weather Service,\nthe Air Force, and the Navy. Each uses the same basic grid system but employs\ndifferent (I, J) indexing conventions. Thus, it is important to know the\noriginator of the gridded product, the specific grid being employed, and its\nrelative indexing convention. This information must be used to properly inter-\npret data related to or defined by COORDINATE FLAG = 1 (see Figures 7.1, 7.2,\nand 10.1) . The designation of the COORDINATE FLAG determines the units for all\ncoordinate data in data blocks that follow it. The originator of the product\ncan be determined from the FILE INDICATOR in the Product Identification Block.\nSpecific details concerning gridded products and indexing conventions should be\nobtained from the agency originating the product.\n10-2","FF\nLENGTH (I)\n007\n020\nPI SET\nGI SET\nSCALE FACTOR\nCOORDINATE FLAG\nUNITS CODE\nSCALE EXPONENT\nMULTIPLIER CONST.\nFIRST BAND INDEX VALUE\nFIRST DELTA BI IN FIELD\nNUMBER OF COLUMNS\nNUMBER OF ROWS\nREFERENCE M COORDINATE\nREFERENCE N COORDINATE\nI START\nJ START\nMONTH\nDAY\nHOUR\nMINUTE\nProduct Valid\nTime\nMONTH\nDAY\nHOUR\nMINUTE\nEnd of Product\nValid Time\nI POLE\nJ POLE\nRE/D\nLONGITUDE X\nREFERENCE CODE\nSCAN CODE\nCHECKSUM\nFigure 10.1\nGridded Data Product Definition Block\nMode 7, Submode 20\n10-3","NOTES: Figure 10.1: Gridded Data Product Definition Block; Mode 7, Submode 20\n1. PI SET: The PI SET defines the background projection on which the product\nis valid. The currently defined codes are shown in Table C2-2 (Annex c). If a\nproduct is not associated with a background, PI SET will be zero (0) filled.\n2. GI SET: The Grid Indicator defines the grid on which the data is valid.\nCurrently defined codes are shown in Table C2-4.\n3. SCALE FACTOR and SCALE FACTOR FRACTION: The real world map scale in\nmillions. The first byte contains the integer part, the second byte contains\nthe fraction.\n4.\nCOORDINATE FLAG: Coordinate System Indicator as follows:\nFlag\nM =\nN =\n0\nLatitude\nLongitude\n(An earth surface grid in\nlatitude and longitude coordi-\nnates.)\n(Cartesian coordinates of the\n1\nI\nJ\nearth's surface.)\n(Pixel coordinates of the pro-\n2\nX\nY\nduct background projection.)\n5. UNITS CODE: A code specifying the units of the data elements. The list of\nunits codes is found in Table C2-6 (Annex C)\n6. SCALE EXPONENT: The number of binary digits scaling which the unpacked\ninteger carries. For example, if N = Scale Exponent, then the Fortran statement\nV = FLOAT(IGRID(J))/2** will convert an unpacked grid value from IGRID(J) into\nthe real parameter value V.\n7. MULTIPLIER CONSTANT: The value that each grid value has been divided by to\nreduce the number of least significant digits.\n8. FIRST BAND INDEX VALUE (BI): This is the Band Index Value at the first grid\npoint. BI(1) = GV(1)/MC. In other words, the BI is the value at the grid point\ndivided by the Multiplier Constant (MC).\n9. FIRST DELTA BI IN FIELD: The difference between the first two BI's Delta\nBI(1) = BI (2) - BI(1).\n10. NUMBER OF COLUMNS: The number of horizontal grids in the grid data area.\n11. NUMBER OF ROWS: The number of vertical grids in the grid data area.\nREFERENCE M and N COORDINATE: These reference coordinates shall specify\n12.\nthe first grid point for which data is transmitted and may represent any point\nin the grid system, usually one of the four corners. M and N are determined by\nthe COORDINATE FLAG.\n10-4","13. ISTART, JSTART: These values designate the starting coordinate of the\nfirst grid point in the first row. The grid points proceed row-wise left-to-\nright NCOLS, then to the next row above and proceed right-to-left and so on up\nto NROWS.\n14. Product/End of Product Valid Time. The Product Valid Time is the time for\nwhich the transmitted data is valid or the start time of the valid period. If\nthe 'DAY' element of the End of Product Valid Time is zero (0), the product is\nvalid only at the Product Valid Time. For observed data, the valid time\napproximates, or may be identical to, the product generation time.\n15. IPOLE/JPOLE: For Polar Stereographic projections, the IPOLE/JPOLE fields\ndefine the horizontal and vertical grid distances respectively, from the pole to\nthe lower left corner of the product. For Mercator projections, the IPOLE\ndefines the East-West grid system distance from the Greenwich meridian to the\nmeridian that passes through the lower left corner of the product, and JPOLE\ndefines the North-South grid system from the equator to the bottom of the\nproduct. For both Polar Stereographic and Mercator projections, the IPOLE/JPOLE\ngrid distances are the number of grid mesh intervals for the product's mesh\nindicated by the GI Set code.\n16. RE/D: For gridded products on polar stereographic background projections,\nthis specifies the effective number of grid lengths from the pole to the equator\non the plane of the projection. It is derived by dividing the distance from the\npole to the equator by the length. The grid length depends on the product's\ngrid mesh, indicated by the GI Set code. For gridded products on Mercator\nbackground projections, RE/D will be set to zero. The actual entry is scaled by\n2**6.\n17. LONGITUDE X : This is the longitude of the meridian perpendicular to the\nbase of the product and extending from the base of the product to the pole.\nLongitude X may be outside of the product boundaries. Table C2-2 shows the\nLongitude X for the defined PI Sets (map projection).\n18. REFERENCE CODE: This code indicates where, in the grid, the reference\ncoordinates are located. The currently used reference codes are:\n1 - Reference coordinates are located in the upper left corner of the grid.\n2 - Reference coordinates are located in the lower left corner of the grid.\n19. SCAN CODE: This code is used to indicate the order in which the data for\nthe grid points appear in the data block. The currently used scan codes are:\n1 - Data are arranged in the data block such that the grid is defined row\nby row (raster scan) from the upper left corner.\n2 - Data are arranged in the data block such that the grid is defined row\nby row (bottom up raster scan) from the lower left corner.\n10-5","LENGTH (I)\nFF :\n007\n001\n2\nDELTA BI VALUES\nCHECKSUM\nFigure 10.2\nBand Index Data Block\nMode 7, Submode 1\nNOTES: Figure 10.2: Band Index Data Block; Mode 7, Submode 1\n2\n1. DELTA BI VALUES: These values are the second derivative of the Band Index\nValues. The field width is set by the Define Datawidth/Fieldwidth Block (Mode\n1, Submode 5) . The default is 8 bits (one byte).\n.\n10-6","ANNEX A\nTERMS, DEFINITIONS AND STANDARD VALUES\nSECTION 1 - GLOSSARY\nSECTION 2 - MNEMONICS\nSECTION 3 - CONSTANTS AND CONVERSION FACTORS\n(Not available with this issuance)\nA","ANNEX A - SECTION 1\nGlossary\nThe degree of conformity of a measured or calculated\nAccuracy\nvalue to some recognized standard or specified value.\nThe process of interpreting and collating independent\nAnalysis\ndata to obtain a comprehensive definition of the state\nof the environment.\nA string of records, a string of words, or a character\nBlock\nstring, formed for technical or logic reasons to be\ntreated as an entity.\nEight contiguous bits ( an octet)\nByte\nA location identifier expressed as a string of alpha-\nCall Letters\nbetic characters.\nA set of items, such as abbreviations, numbers, or\nCode\nstring of alphanumeric characters, that represent the\nmembers of another set of items. For example, the PI\nSET is a code that represents the geographical back-\nground to be used with a product. The term is also used\nto describe a string of alphanumeric characters who\nstructure conveys meaningful information as in weather\nreporting codes.\nTo convert data by reversing the effect of encoding.\nDecode\nThe smallest intelligible component of a product, e.g.,\nElement\nwind speed, wind direction, a four character mnemonic\nthat defines a parameter, symbol, etc.\nA collection of two or more elements related to a\nElement Set\ncomponent of a product, e.g., a weather observation\n(report), group of vectors describing a graphic line,\netc.\nA general term describing three physical areas: the\nEnvironment\nterrestrial environment (the earth itself), the\natmospheric environment (the area above the surface of\nthe earth where weather phenomena occur), and the space\nenvironment (the area extending from approximately the\nbottom of the ionosphere to the sun).\nTo convert data by the use of a code or a code character\nEncode\nset in such a manner that reconversion to the original\nform is possible.\nA1-1","Field\nA bounded collection of data. This term will normally\nbe used with a descriptive adjective that defines the\nnature of the field, e.g., Gridded Data Field, product\nidentification field, etc.\nThe date and time (zulu) a message is made available for\nFile Time\ntransmission purposes.\nFlag\nA bit, combination of bits, or a character, used to\nindicate a class of information, a step in a program, or\nsome classification of a value (commonly used for\nbranching).\nForecast\nA prediction of the future state of the environment.\nGrid\n-A system of uniformly spaced points referenced to the\nphysical surface of the earth. A grid may be in the\nform of uniformly space latitude and longitude points\nwith the spacing expressed in degrees or in the form of\nan array of points with rows designated by an integer\n(I), columns designated by an integer (J), and spacing\nexpressed in nautical miles, kilometers, or some other\nappropriate linear distance. The latter form of grid is\nusually referred to as an I/J grid.\nI/J Grid\nI/J Grid is an array of points in a mapped representa-\ntion of the earth surface and spaced at a uniform\ninterval in the map. The points are referenced by an\ninteger row number (I) and column number (J) There is\na unique algorithm for reference to latitude/longitude\nfrom I/J depending on the map transformation formula\n(i.e., polar stereographic, mercator, Lambert conformal,\netc.) and there is an algorithm for determing the true\nearth distance between grid points (which will in\ngeneral vary over the map).\nImage\nThe visual depiction of information (e.g., a satellite\npicture or a vector graphic product displayed on a CRT).\nLevel\nA surface above the surface of the earth defined by the\nlocus of points of equal atmospheric pressure. It is\nused in connection with upper air data which is reported\nat altitudes dependent on the atmospheric pressure. A\nlevel is therefore a surface on which the pressure is\neverywhere the same.\nLocation Identifier\nA number, or string, of A/N characters that identifies a\ngeographic location (a shorthand notation for name of\nthe location) Location identifiers are assigned by\nseveral different oragnizations (WMO, ICAO, etc.).\nModel\nAn automated set of analysis or forecast algorithms that\nsimulates the dynamics of the environment.\nA1-2","A collection of information describing weather condi-\nObservation\ntions at a specified location within a specified area.\nEight contiguous bits (byte).\nOctet\nA measure of the ability to distinguish between nearly\nPrecision\nequal values. The degree of mutual agreement between\nindividual measurements, namely repeatibility and\nreproducibility.\nA collection of information (element sets) that com-\nProduct\npletely defines a bounded group of related information.\nRecord\nA collection of related data or words treated as a unit,\ne.g., a synoptic observation.\nWhen a figure is to be rounded to fewer digits than the\nRounding\ntotal number available, the procedure should be as\nfollows:\nWhen the first digit discarded is less than five,\na.\nthe last digit retained should not be changed.\nb. When the first digit discarded is five or greater,\nthe last figure retained should be increased by one\nunit.\nA finite or infinite number of objects of any kind, or\nSet\nentities, (of components) or concepts, that have a given\nproperty or properties in common.\nA1-3","ANNEX A - SECTION 2\nMNEMONICS\nTable A2-1\nSymbol, Element, and Line Mnemonics\nUse Code:\n1 = Formatted binary element mnemonic (appearing in Mode 3/Submode 21).\n2 = Formatted binary data block.symbol mnemonic (appearing in Mode\n3/Submode 1).\n3 = Vector graphic line mnemonic (appearing in Mode 1/Submode 4).\n4 = Vector graphic symbol mnemonic (appearing in Mode 5/Submode 2).\n5 = Gridded element mnemonic (appearing in Mode 3/Submode 21)\n6 = Formatted binary element mnemonic (appearing in Mode 3/Submode 22).\nMnemonic\nUse\nDescription\n2,4\nA\nHail\n6\nABA\nAntenna Beam Azimuth\n6\nABE\nAntenna Beam Elevation\n6\nABN\nAntenna Beam Notation\n2,4\nAC\nAltocumulus\n4\nACC\nAnticyclonic Circulation Center\n2,4\nAltocumulus Castellanus (USAF only)\nACC\nACS\n2/4\nAltocumulus Standing Lenticular\nACZ\n3\nAnticyuclonic Wind Shear Zone\nAGE\n1,5\nSnow Age\nAH1-AH6\nArrowhead Style (6 styles)\n3\nALT\n1,5\nAltimeter Setting\n6\nAMI\nAcquisition Mode Identification\nAMX\n1,5\nAmount of Obscuration\nANC\n4\nAnticyclonic Circulation Center (USAF only)\nAOA\n3\nAxis of Advection\nAS\n2,4\nAltostratus\nAUX\n3\nAuxiliary Upper Level Contour\nAW\n2,4\nHail Shower\nAZR\n1,5\nHail Diameter\nBC\n1\nBarometric Characteristic\nBCO-BC8\n2,4\nBarometric Characteritic Trace Code\n2,4\nBD\nBlowing Dust/Sand\nBDP\n5\nBounday Layer Dewpoint Depression\nBDS\n2,4\nDust Storm/Sand Storm\n2,4\nBroken (Sky Condition)\nBKN\nBLK\n1\nWMO Block Number\nA2-1","2,4\nBS\nBlowing Snow\n2,4\nBSH\nBlowing Snow-High\n2,4\nBSL\nBlowing Snow-Low\nCeiling less than 1,000 ft and/or Visibility less than\nB11\n3\n1 mile (area outline)\nCAL\n1\nICAO Cal Letters\n2,4\nCAM\nCloud Amount Missing\nCAT\n3\nClear Air Turbulence Outline\n2,4\nCAO-CA9\nCloud Amount\n2,4\nCB\nCumulonimbus\n2,4\nCB3\nCumulonimbus without Anvil\nCB9\n2,4\nCumulonimbus with Anvil\nCC\n2,4\nCirrocumulus\nCCT\n3,5\nClimatological Temperature\nCCW\n?\nClimatological Wind\nCDB\n1,3,5\nCloud Base\n4\nCold Pool\nCDP\nCloud Top\nCDT\n1,3,5\nCold Front-Aloft\nCFA\n3\nCFG\n3\nCold Frontogenesis\nCFS\n3\nCold Front-Surface\nCFX\n3\nCold Frontolysis\nHigh Cloud Amount\nCHA\n1,5\nHigh Cloud Height\nCHH\n1,5\nCHT\n1\nHigh Cloud Type\nCI\n2,4\nCirrus\nCIG\n1,3,5\nCeling Height\nCLA\n1,5\nLow Cloud Amount\nCLH\n1,5\nLow Cloud Height\n6\nCLQ\nIntegrated Cloud Liquid\n2,4\nClear (Sky Conditioon)\nCLR\nCLT\n1\nLow Cloud Type\nCMA\n1,5\nMiddle Cloud Amount\nCMH\n1,5\nMiddle Cloud Height\nCMT\n1\nMiddle Cloud Height\n2,4\nCS\nCirrostratus\nCT\n1\nCloud Type\nTotal Cloud Amount (USAF only)\nCTA\n1,5\n2,4\nCU\nCumulus\nCVA\n3\nThunderstorm or Convective Area Outline\nCVG\n3\nConvergence Area Outline\n4\nCYC\nCyclonic Circulation Center\nC1A\n1,5\nFirst Cloud Layer Amount\nC1B\n1,5\nContrail Base 1\nC1C\n1,5\nContrail Top 1\nC1H\n1,5\nFirst Cloud Layer Height\nC1T\n1\nFirst Cloud Layer Type\nC2A\n1,5\nSecond Cloud Layer Amount\nC2B\n1,5\nContrail Base 2\nC2C\n1,5\nContrail Top 2\nC2H\n1,5\nSecond Cloud Layer Height\nC2T\n1\nSecond Cloud Layer Type\nC3A\n1,5\nThird Cloud Layer Amount\nA2-2","C3H\n1,5\nThird Cloud Layer Height\nC3T\n1\nThird Cloud Layer Type\nC33\n3\nCeiling less than 3,000 ft and/or Visibility less than\n3 miles (area outline)\n2,4\nD\nDust/Sand - Slight\nDAY\n1\nDay of the Month\nDD\n2,4\nDust Devil\n6\nDFG\nDigitally Filtered Ground clutter removal gates\nDIP\n6\nData Integration Period\nDIR\n1,5,6\nWind Direction\nDIV\n3,5\nDivergence\nDashed Line (seven colors)\nDL1-DL7\n3\nDPD\n1,3,5\nDewpoint Depression\nDPT\n1,3,5,6\nDewpoint Temperature\nDRY\n3\nDry Line\nDVL\n3,5\nD-Value\nCeiling less than 10,000 ft (area outline)\nD10\n3\nELV\n6\nElevation (msl meters)\nEPT\n5\nEquivalent Potential Temperature\nF\n2,4\nFog/Ice Fog\n6\nRadial distance to center of first radar gate (meters)\nFGD\nHeight (vertical) to center of first gate (meters)\nFGH\n6\nFNL\n2,4\nFunnel Cloud\nFPH\n2,4\nFog during past hour\nGF\n2,4\nGround Fog\n6\nGMH\nGeometric heights\nGPH\n1,3,5,6\nGeopotential Height\nGST\n1\nWind Gust\n2,4\nH\nHaze\nAltitude (Height)\nHGT\n1,3,5\nHI\n4\nHigh Pressure/Height Center\nHR\n1,6\nHour\nHSS\n3\nHorizontal Speed Shear\nHTF\n3\nHeight Fall Area Outline\nI\n3\nIcing\nICE\n3\nIce Cover\nICG\n3\nIcing Area Outline\nICL\n4\nClear Icing - Light\n4\nICM\nClear Icing - Moderate\n4\nICS\nClear Icing - Severe\n4\nICT\nClear Icing - Trace\nIDT\n6\nInstrument Dwell Time\n2,4\nIce Fog (USAF only)\nIF\nIML\n4\nMixed Icing - Light\nIMM\n4\nMixed Icing - Moderate\nIMS\n4\nMixed Icing - Severe\nIMT\n4\nMixed Icing - Trace\nA2-3","4\nShear/Instability Line\nINS\n2,4\nIP\nIce Pellets\n2,4\nIPW\nIce Pellet Shower\n2,4\nIce Prisms\nIPZ\n4\nIRL\nRime Icing - Light\n4\nRime Icing - Moderate\nIRM\n4\nIRS\nRime Icing - Severe\n4\nIRT\nRime Icing - Trace\nJLH\n1\nJulian Hour\nK\n2,4\nSmoke\n2,4\nL\nDrizzle/Moderate Drizzle\n2,4\nL+\nHeavy Drizzle\n2,4\nLight Drizzle\nL-\n1,6\nLatitude\nLAT\nLess than 2/8 Cloud Cover ( area outline)\nLES\n3\n4\nLow Pressure/Height Center\nLO\n1,6\nLON\nLongitude\nLPH\n2,4\nDrizzle during past hour\nLTG\n2,4\nLightning\nCloud Amount Layer 1-4 (4 layers) (USAF only)\nL1A-L4A\n1\nCloud Height Layer 1-4 (4 layers) (USAF only)\nL1H-1\n1\nCloud Type Layer 1-4 (4 layers) (USAF only)\nL1T-L4T\n1\nMDV\n3,5\nMedium Range D-Value\n1,6\nMN\nMinute\n4\nMNS\nMinus Sign\n6\nMO\nMaximum Wind Level 1-3 (3 levels)\nMW1-MW3\n1\n6\nNRG\nNumber of Range Gates\n2,4\nNS\nNimbostratus\n6\nNSA\nNumber of Spectral Averages\n6\nNull, or fields to be ignored\nNUL\n2,4\nObscured (Sky Condition)\nOBS\nOFA\n3\nOccluded Front-Aloft\nOFS\n3\nOccluded Front-Surface\nOFX\n3\nOccluded Frontolysis\n6\nOPF\nCenter operating frequency\n2,4\nOvercast (Sky Condition)\nOVC\nOVV\n3,5\nOmega/Vertical Velocity\nPC3\n1\nPressure Characteristic - 3 hr\nPKG\n1\nPeak Gust\n4\nPLS\nPlus Sign\n6\nPNN\nProcessing No de Name\nBarometric tendency (3-hour pressure change)\nPP\n1,3\nPPP\n1,3\nSea Level Pressure\n1,5,6\nPPW\nPrecipitable Water\n6\nPRP\nPulse Repetition Period\n1,5,6\nPRS\nPressure\nA2-4","Positive Vorticity Advection Line\nPVA\n3\n2,4\nPast Weather - Blowing Dust or Snow\nPWB\n2,4\nPast Weather - Fog\nPWF\n2,4\nPast Weather - Drizzle\nPWL\n2,4\nPast Weather - Rain\nPWR\n2,4\nPast Weather - Snow\nPWS\n2,4\nPast Weather - Thunderstorm\nPWT\n2,4\nPast Weather - Showers\nPWW\nPWX\n1\nPast Weather\nQPF\n3,5\nQuantitative Precipitation Forecast\n4,6\nSpecial Symbol 1-9 (defined by originator\nQQ1-QQ9\nof product)\n2,4\nRain/Moderate Rain\nR\n2,4\nHeavy Rain\nR+\n2,4\nR-\nLight Rain\n6\nRadar Acquisition Mode\nRAM\nRidge Axis\nRDG\n3\n6\nRadar Mean Velocity\nRMV\n6\nRadar Noise Level estimate\nRNL\n2,4\nRain During Past Hour\nRPH\n6\nRadar Pulse Width\nRPW\n2,4\nRain and Snow Mixed\nRS\n6\nRadar Spectral Data values\nRSD\n6\nRadar Sampling Interval\nRSI\n6\nRSN\nRadar Site Name\n6\nRadar Signal Power\nRSP\n2,4\nShowers of Rain and Snow Mixed\nRSW\n6\nRadar velocity variance\nRVV\n2,4\nRW\nRain Showers\nR06\n6-Hour Precipitation Amount\n1,3,5\nR24\n1,3,5\n24-Hour Precipitation Amount\n2,4\nSnow/Moderate Snow\nS\n2,4\nS+\nHeavy Snow\n2,4\nLight Snow\nS-\n2,4\nSC\nStratocumulus\n2,4\nScattered (Sky Condition)\nSCT\nShip Direction (USAF Only)\nSD\n1\nSDD\n1\nShip Direction\n4\nSubtropical Depression\nSDP\nShip Direction 0-8 (9 values: becalmed & 8 points\nSD0-SD8\n2,4\nof compass clockwise from NE)\nStationary Front - Aloft\nSFA\n3\nSFG\n3\nStationary Frontogenesis\nStationary Front - Surface\nSFS\n3\nStationary Frontolysis\nSFX\n3\n2,4\nSnow Grains (USAF only)\nSG\n2,4\nSGR\nSnow Grains\nSky Cover (Total Cloud Amount)\nSKY\n1,5\nSolid LLine 1-7 (7 colors)\nSL1-SL7\n3\nSnow Depth\nSNO\n3,5\n6\nSignal-to-noise ratios\nSNR\nA2-5","SOA\n3\nStationary Occluded Front - Aloft\nSOS\n3\nStationary Occluded Front - Surface\nSOX\n3\nStationary Occluded Frontolysis\nSPD\n1,3,5,6\nWind Speed\nSPH\n2,4\nSnow During Past Hour\nSPL\n6\nMinimum signal power used in scaling\nSPW\n6\nMaximum signal power used in scaling\nSQL\n2,4\nSqualls\nSRN\n6\nSoftware Revision Number\nSRP\n6\nStandard Reporting Period\nSSN\n4\nSubtropical Storm - Northern Hemisphere\nSSS\n1,3,5\nSea Surface Temperature\nST\n2,4\nStratus\nSTF\n3,5\nStream Function Value\nSTM\n3,5\nStreamline\nSTN\n1\nWMO Station Number\nSV\n1\nShip Speed (USAF only)\nSVH\n6\nMaximum spectral value over all spectra\nSVL\n6\nMinimum spectral vaalue over all spectra\nSVV\n1\nShip Speed\nSW\n2,4\nSnow Showers\nSWT\n1,3,5\nSWEAT Index\nS06\n1,3,5\n6-Hour Snowfall Amount\nT\n2,4\nThunderstorm\nTA\n2,4\nThunderstorm with Hail\nTBB\n6\nBrightness temperatures\nTBL\n4\nTurbulence - Light\nTBM\n4\nTurbulence - Moderate\nTBS\n4\nTurbulence - Severe\nTCN\n4\nTropical Cyclone - Northern Hemisphere\nTCS\n4\nTropical Cyclone - Southern Hemisphere\nTCU\n2,4\nTowering Cumulus\nTDA\n6\nNumber of time domain averages (coherent averages)\nTDP\n4\nTropical Depression\nTMP\n1,3,5,6\nTemperature\nTPH\n2,4\nThunderstorm During Past Hour\nTP1-TP3\n1,3\nTropopause Level 1-3 (3 levels)\nTPP\n6\nTropopause height\nTRO\n3\nTrough Axis\nTRP\n4\nTriple Point\nTRS\n2,4\nThunderstorm with Rain and Snow Mixed\nTRW\n2,4\nThunderstorm with Rainshower\nTR7\n3\n700 mb Temperature Ridge\n6\nTSD\nTime Series Data\nTSP\n6\nNumber of time series points (= FFT points)\nTSN\n4\nTropical Storm - Northern Hemisphere\nTSS\n4\nTropical Storm - Southern Hemisphere\nTSW\n2,4\nThunderstorm with Snowshower\nTTN\n1,3,5\nMinimum Temperature\nTTX\n1,3,5\nMaximum Temperature\nTXT\n6\nInformational text messages\nA2-6","5,6\nUWC\nU Wind Component\n6\nVGS\nVertical inter-range gate spacing (center to center)\n6\nVertical range gate width (meters)\nVGW\nVIS\n1,3,5\nVisibility\n4\nVMC\nVorticity Maximum\nVRT\n3,5\nVorticity\n5,6\nVWC\nV Wind Component\nWBC\n4\nWind Barb - 100 knots\n4\nWBI\nWind Barb - 1 or 2 knots\n4\nWBL\nWind Barb - 50 knots\n4\nWBV\nWind Barb - 5 knots\n4\nWBX\nWind Barb - 10 knots\n2,4\nWDM\nWind Direction Missing\nWET\n3\nNon-Convective or Intermittent Precipitation\n(area outline)\nWarm Front-Aloft\nWFA\n3\nWFG\n3\nWarm Frontogenesis\nWFS\n3\nWarm Frontolysis\nWFX\n3\nWarm Frontolysis\nWMP\n4\nWarm Pool\n2,4\nWNC\nCalm Wind\nWPH\n2,4\nShowers During Past Hour\nWSM\n2,4\nWind Speed Missing\nWVD\n1\nWave Direction\nWVH\n1\nWave Height\nWW1\n1,5\nPrimary Present Weather\nWW2\n1,5\nSecondary Present Weather\nWW34\n1,5\nTertiary Present Weather\n6\nW (vertical) wind component\nWWC\n2,4\nZL\nFreezing Drizzle\nZPH\n2,4\nFreezing Precipitation During Last Hour\nZR\n2,4\nFreezing Rain\nSpecial Parameter 1-9 (9 parameters)\nZZ1-ZZ9\n1,3,5,6\nA2-7","ANNEX A - SECTION 2\nDATA BLOCK DATA CODE\nWITH\nCORRESPONDING MNEMONICS\nTable A2-2\nNOTE: Formatted binary products originating from the USAF do not use mnemonics\nin the formatted binary data block (Use Code 2 in Table A2-1). Certain\nformatted binary element mnemonics use a binary data block code, making data\nbinary in Mode 3/Submode 1. The following shows the element description\nmnemonic (which could appear in Mode 3/Submode 21), the data block data code\n(which could then appear in Mode 3/Submode 1), , and the mnemonic to which that\ndata code corresponds.\nData Description\nData Block\nCorresponding\nDescription\nMnemonic\nData Code\nMnemonic\nBarometric Characteristic\nBC\n0 - Rising then falling\n160\nBCO\n1 - Rising then steady\n161\nBC1\n2 - Rising\n162\nBC2\n3 - Falling or steady, then rising\n163\nBC3\n4 - Steady\n164\nBC4\n5 - Falling then rising\n165\nBC5\n6 - Falling then steady\n166\nBC6\n7 - Falling\n167\nBC7\n8 - Steady or rising, then falling\n168\nBC8\nCloud Amount Total\nCTA\nM - Missing\n149\nCAM\n0 - No Clouds (Airways clear)\n150\nCAO,CLR\n1 - One tenth\n151\nCA1\n2 - Two to three tenths (Airways scattered)\n152\nCA2,SCT\n3 - Four tenths\n153\nCA3\n4 - Five tenths\n154\nCA4\n5 - Six tenths\n155\nCA5\n6 - Seven to eight tenths (Airways broken)\n156\nCA6,BKN\n7 - Nine tenths\n157\nCA7\n8 - Ten tenths (Airways overcast)\n158\nCA8,OVC\n9 - Obscured\n159\nCA9,OBS\nPresent Weather\nPresent Weather (primary)\nWW1\nPresent Weather (Secondary)\nWW2\nPresent Weather (tertiary)\nWW3\nA2-8","No Weather Reportable\n000\nSmoke\n004\nK\nHaze\n005\nH\nDust/Sand\n006\nD\nBlowing Dust/Sand\n007\nBD\nDust Devil\n008\nDD\nLightning\n013\nLTG\nThunderstorm\n017\nT\nSqualls\n018\nSQL\nFunnel Cloud\n019\nFNL\nDrizzle during past hour\n020\nLPH\nRain during past hour\n021\nRPH\nSnow during past hour\n022\nSPH\nFreezing precipitation during last hour\n024\nZPH\nShowers during past hour\n025\nWPH\nFog during past hour\n028\nFPH\nThunderstorm during past hour\n029\nTPH\nDust Storm/Sand Storm\n031\nBDS\nBlowing Snow\n038\nBS\nGround Fog\n044\nGF\nFog\n045\nF\nIce Fog\n049\nIF\nDrizzle, light\n051\nL-\nDrizzle, moderate\n053\nL\nDrizzle, heavy\n055\nL+\nFreezing Drizzle\n056\nZL\nRain, light\n061\nR-\nRain, moderate\n063\nR\nRain, heavy\n065\nR+\nFreezing Rain\n066\nZR\nRain and Snow Mixed\n068\nRS\nSnow, light\n071\nS-\nSnow, moderate\n073\nS\nSnow, heavy\n075\nS+\nIce Prisms\n076\nIPZ\nSnow Grains\n077\nSG, SGR\nIce Pellets\n079\nIP\nRain Showers\n080\nRW\nShowers of Rain and Snow Mixed\n083\nRSW\nSnow Showers\n085\nSW\nIce Pellet Shower\n087\nIPW\nHail Shower\n089\nAW\nThunderstorm with Rainshower\n093\nTRW\nThunderstorm with Snowshower\n094\nTSW\nThunderstorm with Rain and Snow Mixed\n095\nTRS\nThunderstorm with Hail\n096\nTA\nCloud Type Layer 1\nL1T\nCloud Type Layer 2\nL2T\nCloud Type Layer 3\nL3T\nCloud Type Layer 4\nL4T\nA2-9","Cloud Type (layer 1 - 4) Codes\nCumulus (low cloud 1,8)\n111\nCU\nTowering Cumulus (low cloud 2)\n112\nTCU\nCumulonimbus without Anvil (low cloud 3)\n113\nCB,CB3\nStratocumulus (low cloud 4,5)\n114\nSC\nStratus (low cloud 6,7)\n116\nST\nCumulonimbus with Anvil (low cloud 9)\n119\nCB, CB9\nAltostratus (middle cloud 1)\n121\nAS\nNimbostratus (middle cloud 2)\n122\nNS\nAltocumulus (middle Cloud 3,5,6,7,9)\n123\nAC\nAltocumulus Standing Lenticular (middle cloud 4)\n124\nACS\nAltocumulus Castellanus (middle cloud 8)\n128\nACC\nCirrus (high cloud 1,2,3,4)\n131\nCI\nCirrostratus (high cloud 5,6,7,8)\n135\nCS\nCirrocumulus (high cloud 9)\n139\nCC\nPast Weather\nPWX\nPWB\nBlowing dust or snow\n103\n104\nPWF\nFog\nDrizzle\n105\nPWL\n106\nPWR\nRain\nSnow\n107\nPWS\n108\nPWW\nShowers\n109\nPWT\nThunderstorm\nShip Direction\nSD\nBecalmed\n170\nSDO\nNE\n171\nSD1\n172\nSD2\nE\nSE\n173\nSD3\n174\nSD4\nS\n175\nSD5\nSW\n176\nSD6\nW\nNW\n177\nSD7\n178\nSD8\nN\n186\nMissing Wind Direction\nWDM\n188\nMissing Wind Speed\nWSM\nA2-10","Table A2-3\nOther Mnemonics Used in This Report\nMnemomics\nDescription\nAFGWC\nAir Force Global Weather Central\nANSI\nAmerican National Standards Institute\nASCII\nAmerican Standard Code for Information Interchange\nAWS\nAir Weather Service\nA/N\nAlphanumeric\nBI\nBand Index\nCPC\nCalcomp Pen Command\nCPU\nCentral Processing Unit\nDB\nData Blocks\nDDB\nData Description Block\nEOM\nEnd of Map\nEOS\nEnd of Scan\nETB\nEnd of Text Block\nETX\nEnd of Text\nFAA\nFederal Aviation Administration\nFF\nFlag (2-bit indicator)\nGI\nGrid Indicator\nGMT\nGreenwich Mean Time\nGV\nGrid Value\nH\nHemisphere\nICAO\nInternational Civil Aviation Organization\nInitial Direction (Vector)\nIDV\nI/J\nCartesian Coordinate Set (reference earth surface)\nIL\nIncrement Length (Vector)\nIPOLE/JPOLE\nGrid Coordinates of the North or South Pole\nLAT/LON\nLatitude/Longitude Coordinates\nMC\nMultiplier Constant\nM/N\nGeneralized Coordinate Set\nNBS\nNational Bureau of Standards\nNCHAR\nNumber of Characters (in product title)\nNWS\nNational Weather Service\nOCT\nOctant\nPDB\nProduct Definition Block\nPI\nProjection (map) Indicator\nA2-11","Projection Indicator Set. A code that defines the back-\nPI SET\nground geographic projection on which the transmitted\nproduct is valid. The PI SET provides the means by\nwhich products can be registered to geography.\nEffective Number of Grid Points from Pole to Equator\nRE/D\nVEV\nVariable Exception Vector\nWorld Meteorological Organization\nWMO\nXMAX\nMaximum Horizontal Size\nXROW/YCOL\nPixel Coordinates for Scan Lines\nPixel Coordinate Set (reference display area)\nX/Y\nYMAX\nMaximum Vertical Size\nGreenwich Mean Time (GMT)\nZ\nZ\nZoom Disable Indicator\nA2-12","ANNEX B\nREFERENCES\n(TBA)\n(Refer to applicable FIPS and other accepted standards) .\nB","ANNEX C\nCODE TABLES\nSECTION 1\nGENERAL\nSECTION 2\nMETEOROLOGICAL PROGRAM CODES\nSECTION 3\nMISCELLANEOUS\n(Not available with this issuance)\nC","ANNEX C - SECTION 1\nTable 1\nStandard ASCII Code\nOCTAL\nHEXADECIMAL\nMNEMONIC\nMEANING\n000\n00\nNUL\nNull\n001\n01\nSOH\nStart of Heading\n002\n02\nSTX\nStart of Text\n003\n03\nETX\nEnd of Text\n004\n04\nEOT\nEnd of Transmission\n005\n05\nENQ\nEnquiry\n006\n06\nACK\nAcknowledge\n007\n07\nBEL\nBell\n010\n08\nBS\nBackspace\n011\n09\nHT\nHorizontal Tabulation\n012\nOA\nLF\nLine Feed\n013\nOB\nVT\nVertical Tabulation\n014\nOC\nFF\nForm Feed\n015\nOD\nCR\nCarriage Return\n016\nOE\nso\nShift Out\n017\nOF\nSI\nShift In\n020\n10\nDLE\nData Link Escape\n021\n11\nDC1\nDevice Control 1\n022\n12\nDC2\nDevice Control 2\n023\n13\nDC3\nDevice Control 3\n024\n14\nDC4\nDevice Control 4\n025\n15\nNAK\nNegative Acknowledge\n026\n16\nSYN\nSynchronous Idle\n027\n17\nETB\nEnd of Transmission Block\n030\n18\nCAN\nCancel\n031\n19\nEM\nEnd of Medium\n032\n1A\nSUB\nSubstitute\n033\n1B\nESC\nEscape\n034\n1C\nFS\nFile Separator\n035\n1D\nGS\nGroup Separator\n036\n1E\nRS\nRecord Separator\n037\n1F\nUS\nUnit Separator\n040\n20\nSP\nSpace (nonprinting)\n041\n21\n!\nExclamation Point\n042\n22\nIf\nQuotation Marks (Diaeresis)\n043\n23\n#\nNumber Sign (Note 1)\n044\n24\n$\nDollar Sign\n045\n25\n%\nPercent Sign\n046\n26\n&\nAmpersand\n047\n27\n1\nApostrophe (Closing single\nquote, Acute Accent)\nC1-1","Opening Parenthesis\n(\n28\n050\nClosing Parenthesis\n)\n051\n29\n*\nAsterisk\n052\n2A\nPlus\n053\n2B\n+\nComma (Cedilla)\n054\n2C\n,\nHyphen (Minus)\n055\n2D\n-\nPeriod (Decimal Point)\n056\n2E\n/\nSlant\n057\n2F\nDigit\n060\n30\n0\nDigit\n061\n31\n1\nDigit\n062\n32\n2\n063\n33\n3\nDigit\n4\nDigit\n064\n34\nDigit\n065\n35\n5\n6\nDigit\n066\n36\nDigit\n067\n37\n7\n8\n38\nDigit\n070\nDigit\n9\n071\n39\nColon\n072\n3A\n:\nSemicolon\n073\n3B\n;\nLess Than\n074\n3C\n<\nEquals\n075\n3D\n=\nGreater Than\n076\n3E\n>\nQuestion Mark\n?\n077\n3F\nCommercial At (Note 1)\n40\n@\n100\nUpper Case Latin Letter\n41\nA\n101\nUpper Case Latin Letter\n42\nB\n102\nUpper Case Latin Letter\n43\nC\n103\nUpper Case Latin Letter\n104\n44\nD\nUpper Case Latin Letter\n45\nE\n105\nUpper Case Latin Letter\n46\n106\nF\nUpper Case Latin Letter\n47\nG\n107\nUpper Case Latin Letter\n48\nH\n110\nUpper Case Latin Letter\n49\nI\n111\nUpper Case Latin Letter\n4A\nJ\n112\nUpper Case Latin Letter\n4B\nK\n113\nUpper Case Latin Letter\n114\n4C\nL\nUpper Case Latin Letter\n4D\nM\n115\nUpper Case Latin Letter\n116\n4E\nN\nUpper Case Latin Letter\n4F\n0\n117\nUpper Case Latin Letter\n120\n50\nP\nUpper Case Latin Letter\nQ\n121\n51\nUpper Case Latin Letter\n122\n52\nR\nUpper Case Latin Letter\n123\n53\nS\nUpper Case Latin Letter\n124\n54\nT\nUpper Case Latin Letter\n125\n55\nU\nUpper Case Latin Letter\n126\n56\nV\nUpper Case Latin Letter\nW\n127\n57\nC1-2","130\n58\nX\nUpper Case Latin Letter\n131\n59\nY\nUpper Case Latin Letter\n132\n5A\nZ\nUpper Case Latin Letter\n133\n5B\n[\nOpening Bracket (Note 1)\n134\n5C\n\\\nReverse Slant (Note 1)\n135\n5D\n]\nClosing Bracket (Note 1)\n136\n5E\nCircumflex (Note 1)\n137\n5F\nUnderline\n140\n60\n1\nOpening Single Quotation Mark\n(Grave Accent) (Note 1)\n141\n61\nLower Case Latin Letter\na\n142\n62\nb\nLower Case Latin Letter\n143\n63\nLower Case Latin Letter\nC\n144\n64\nd\nLower Case Latin Letter\n145\n65\nLower Case Latin Letter\ne\n146\n66\nf\nLower Case Latin Letter\n147\n67\nLower Case Latin Letter\ng\n150\n68\nh\nLower Case Latin Letter\n151\n69\ni\nLower Case Latin Letter\n152\n6A\nj\nLower Case Latin Letter\n153\n6B\nk\nLower Case Latin Letter\n154\n6C\n1\nLower Case Latin Letter\n155\n6D\nm\nLower Case Latin Letter\n156\n6E\nLower Case Latin Letter\nn\n157\n6F\nLower Case Latin Letter\no\n160\n70\nLower Case Latin Letter\np\n161\n71\nLower Case Latin Letter\nq\n162\n72\nLower Case Latin Letter\nr\n163\n73\nS\nLower Case Latin Letter\n164\n74\nt\nLower Case Latin Letter\n165\n75\nu\nLower Case Latin Letter\n166\n76\nV\nLower Case Latin Letter\n167\n77\nW\nLower Case Latin Letter\n170\n78\nX\nLower Case Latin Letter\n171\n79\nLower Case Latin Letter\ny\n172\n7A\nLower Case Latin Letter\nZ\n173\n7B\n{\nOpening Brace (Note 1)\n174\n7C\nVertical Line (Note 1)\n175\n7D\n}\nClosing Brace (Note 1)\n176\n7E\nTilde (Note 1)\n177\n7F\nDEL\nDelete\nNOTE 1: Should be checked for international exchange.\nC1-3","ANNEX C - SECTION 2\nTable C2-1\nASCII - Symbology Conventions\nC2-1","ANNEX C - Section 2\nTable C2-2\nProjection Indicator (PI) Set Codes\nNOTES:\nProjection reference latitudes are 6ON for Northern Hemisphere polar\n1.\nstereographic and 22.5N and 22.5S for Mercator.\n2. Projection (polar stereographic, Mercator), Longitude X (except Mercator),\nand ASCII Descriptor for the LAWC PI Set Codes will be determined by mutual\nagreement between the exchanging agencies controlling the weather information\nsystems involved in the data exchange.\n3. The following linear size ratios apply for polar stereographic;\nHemispheric = 6:1\nContinental/Oceanic = 3:1\nRegional Window = 2:1\nSubwindow = 1:1\n4. The following linear size ratios apply for Mercator:\nTropical Continental/Ocean = 3:1\nRegional Window = 2:1\nSubwindow = 1:1\n5. Lower left corner points are in units of the USAF AFGWC whole mesh Satellite\nGlobal Data Base (SGDB) grid. The area coverage of the hemispheric projections\nare always 49 X 49 whole mesh SGDB grid points. The Continental/Ocean\nare\nalways 25 X 25. The Regional are always 17 X 17. The Subwindows are 9 X 9.\nThe SGDB grid point values can be converted to NMC and FNOC whole mesh grid\npoint values.\nC2-2","ANNEX C - Section 2\nTable C2-2\nProjection Indicator (PI) Set Codes\nLOWER LEFT CORNER\nPI\nPOINT\nASCII\nSET\nPROJECTION LONG X\nROW\nCOLUMN\nDESCRIPTOR\nCODE DESCRIPTION\n00\nNo Background\n80W\nPolar\n9\n57\nXW\n1\nN. Hemisphere\nStereographic\nUS\nPolar\n10E\n57\n57\nXN\n2\nN. Hemisphere\nStereographic\nEurope\nXP\nPolar\n170W\n9\n9\n3\nN. Hemisphere\nStereographic\nPacific\n4\n100E\n57\n9\nXE\nN. Hemisphere\nPolar\nStereographic\nAsia\nPolar\n100E\n9\n57\nXS\n5\nS. Hemisphere\nStereographic\n- 9 (Not Assigned)\n6\n80W\n10\nCont/Ocean\nPolar\n17\n57\nNA\nStereographic\nN. America\n80W\nPolar\n29\n53\nNT\n11\nCont/Ocean\nAtlantic (US)\nStereographic\n10E\n53\n53\nEW\n12\nCont/Ocean\nPolar\nAtlantic (Europe)\nStereographic\n36\nAS\n13\nCont/Ocean\nPolar\n10E\n57\nStereographic\nEurasia\n14\nPolar\n170W\n9\n9\nPQ\nCont/Ocean\nN.W. Pacific\nStereographic\n9\n25\nPN\n15\nCont/Ocean\nPolar\n170W\nStereographic\nN.E. Pacific\n9\nFE\n16\nCont/Ocean\nPolar\n100E\n33\nStereographic\nFar East\n17 - 30 (Not Assigned)\nC2-3","ANNEX C - Section 2\nTable C2-2\nProjection Indicator (PI) Set Codes\nPI\nLOWER LEFT CORNER\nSET\nPOINT\nASCII\nCODE\nDESCRIPTION\nPROJECTION LONG X\nROW\nCOLUMN\nDESCRIPTOR\n31\nRegional Window\nMercator\n69\n19\nCA\nCaribbean\n.\n32\nRegional Window\nMercator\n47\n19\nTR\nTropical Hawaiian\nIslands\n33\nRegional Window\nMercator\n31\n19\n-\nMY\nMarianas\n34\nRegional Window\nMercator\n25\n19\nID\nS.E. Asia\n35 - 39 (Not Assigned)\n40\nRegional Window\nPolar\n80W\n21\n55\nUS\nCONUS\nStereographic\n41\nRegional Window\nPolar\n80W\n25\n57\nUE\nEast US\nStereographic\n42\nRegional Window\nPolar\n80W\n17\n57\nUW\nWest US\nStereographic\n43\nRegional Window\nPolar\n80W\n17\n49\nUN\nNorth US\nStereographic\n44\nRegional Window\nPolar\n80W\n25\n49\nCN\nCanada\nStereographic\n45\nRegional Window\nPolar\n10E\n52\n39\nEU\n-\nEurope\nStereographic\n46\nRegional Window\nPolar\n100E\n33\n12\nJN\n.\nEast Asia\nStereographic\n47\nRegional Window\nPolar\n170W\n18\n27\nAQ\nAlaska\nStereographic\n48\nRegional Window\nPolar\n170W\n7\n31\nPA\nHawaii\nStereographic\n49\nRegional Window\nPolar\n10E\n49\n50\nAZ\nAzores\nStereographic\nC2-4","ANNEX C - Section 2\nTable C2-2\nProjection Indicator (PI) Set Codes\nLOWER LEFT CORNER\nPI\nPOINT\nSET\nASCII\nCODE DESCRIPTION\nPROJECTION LONG X\nROW\nCOLUMN\nDESCRIPTOR\n50 - 59 (Not Assigned)\n60\nTropical Cont/Ocean Mercator\n9\n27\nIO\nIndian Ocean\n61\nTropical Cont/Ocean Mercator\n31\n27\nPW\nW. Pacific\n62\nTropical Cont/Ocean Mercator\n53\n27\nPZ\nE. Pacific\n63\n63\nTropical Cont/Ocean Mercator\n27\nSA\nW. Hemisphere\n64\nTropical Cont/Ocean Mercator\n73\n27\nST\nAtlantic\n65\nTropical Cont/Ocean Mercator\n90\n27\nAF\nAfrica\n66 - 69 (Not Assigned)\n80W\nUM\n70\nSubwindow\nPolar\n21\n47\nUS (N.W.)\nStereographic\n80W\n19\n50\nUA\n71\nSubwindow\nPolar\nUS (West)\nStereographic\n80W\n72\nSubwindow\nPolar\n22\n50\nUC\nUS (Mountain)\nStereographic\n80W\n22\n53\nUX\n73\nSubwindow\nPolar\nUS (S.W.)\nStereographic\n80W\n74\nSubwindow\nPolar\n25\n50\nUD\nUS (N. Central) )\nStereographic\n80W\n25\n53\nUL\n75\nSubwindow\nPolar\nUS (S. Central)\nStereographic\n80W\n28\n76\nPolar\n52\nUO\nSubwindow\nUS (East)\nStereographic\nC2-5","ANNEX C - Section 2\nTable C2-2\nProjection Indicator (PI) Set Codes\nPI\nLOWER LEFT CORNER\nSET\nPOINT\nASCII\nCODE DESCRIPTION\nPROJECTION LONG X\nROW\nCOLUMN\nDESCRIPTOR\n77 Subwindow\nPolar\n80W\n31\n51\nUP\nUS (N.E.)\nStereographic\n78\nSubwindow\nPolar\n80W\n28\n55\nUF\nUS (S.E.)\nStereographic\n79\nSubwindow\nPolar\n80W\n18\n45\nUB\n-\nUS (N.E. Pacific)\nStereographic\n80\nSubwindow\nPolar\n48\n10E\n38\nUK\nW. Europe\nStereographic\n81\nSubwindow\n44\n40\nPolar\n10E\nIL\nIceland\nStereographic\n82\nSubwindow\nPolar\n10E\n51\n40\nSP\nSpain\nStereographic\n83\nSubwindow\nPolar\n10E\n51\n36\nIY\nItaly\nStereographic\n84\nSubwindow\nPolar\n10E\n51\n31\nTU\nTurkey\nStereographic\n85\nSubwindow\nPolar\n10E\n45\n32\nRS\nUSSR\nStereographic\n86 - 89 (Not Assigned)\n90\nSubwindow\nPolar\n170W\n22\n31\nAK\n-\nAlaska\nStereographic\n91\nSubwindow\nPolar\n170W\n26\n27\nAC\nAlaska (Arctic)\nStereographic\n92\nSubwindow\nPolar\n170W\n26\n35\nAY\nAlaska (NW Canada)\nStereographic\n93\nSubwindow\nPolar\n170W\n18\n35\nGA\nAlaska (Gulf)\nStereographic\n94\nSubwindow\nPolar\n170W\n18\n27\nLU\nAlaska (Bering Sea)\nStereographic\nC2-6","ANNEX C - Section 2\nTable C2-2\nProjection Indicator (PI) Set Codes\nPI\nLOWER LEFT CORNER\nSET\nPOINT\nASCII\nCODE DESCRIPTION\nPROJECTION LONG X\nROW\nCOLUMN\nDESCRIPTOR\n95 - 99 (Not Assigned)\n100\nSubwindow\nPolar\n170W\n7\n34\nHW\nHawaii\nStereographic\n101\nSubwindow\nPolar\n170W\n16\n31\nHF\nHawaii (NW)\nStereographic\n102 Subwindow\nPolar\n170W\n16\n39\nHG\nHawaii (NE)\nStereographic\n103\nSubwindow\nPolar\n170W\n7\n39\nHH\nHawaii (E)\nStereographic\n104\nSubwindow\nPolar\n170W\n7\n31\nHI\nHawaii (W)\nStereographic\n105 - 109 (Not Assigned)\n110\nSubwindow\nPolar\n100E\n30\n15\nKO\nKorea\nStereographic\n111\nSubwindow\nPolar\n100E\n27\n17\nJP\nJapan\nStereographic\n112\nSubwindow\nPolar\n100E\n28\n12\nEC\nOkinawa\nStereographic\n113 Subwindow\nPolar\n100E\n33\n20\nMK\nAsia (E USSR)\nStereographic\n114\nSubwindow\nPolar\n100E\n25\n20\nJH\nAsia (NW Pacific)\nStereographic\n115 Subwindow\nPolar\n100E\n25\n12\nJK\nAsia (W Cen Pacific) Stereographic\n116\nSubwindow\nPolar\n100E\n33\n12\nCI\nAsia (China)\nStereographic\n117 - 119 (Not Assigned)\n120\nSubwindow\nPolar\n10E\n49\n46\nLJ\nLajes\nStereographic\nC2-7","ANNEX C - Section 2\nTable C2-2\nProjection Indicator (PI) Set Codes\nLOWER LEFT CORNER\nPI\nPOINT\nASCII\nSET\nCOLUMN\nCODE DESCRIPTION\nPROJECTION LONG X\nROW\nDESCRIPTOR\n41\n50\nNF\n121\nSubwindow\nPolar\n10E\nLajes (NW Atlantic)\nStereographic\n41\n42\nGL\n122 Subwindow\nPolar\n10E\nLajes (Iceland)\nStereogrphic\n49\n42\nPO\n123 Subwindow\nPolar\n10E\nLajes (NE Atlantic)\nStereographic\n49\n124 Subwindow\nPolar\n10E\n50\nAX\nLajes (NC Atlantic)\nStereographic\n125 - 129 (Not Assigned)\n14\nPM\n130 Subwindow\nMercator\n72\nPanama\nGX\n131 Subwindow\nMercator\n70\n12\nGulf of Mexico\nHT\n132 Subwindow\nMercator\n51\n13\nTropical Hawaii\n14\nGM\n133 Subwindow\nMercator\n35\nGuam\n14\n134 Subwindow\nMercator\n27\nSS\nS. China Sea\nPH\n135 Subwindow\nMercator\n32\n11\n-\nPhilippine Sea\n136 - 149 (Not Assigned)\n.\n150\nLAWC #1\n151\nLAWC #2\n152\nLAWC #3\nC2-8","ANNEX C - Section 2\nTable C2-3\nPlot Process Codes\nCode Value\n(Octal)\nMeaning\n0\nThe character data within the block represent alphanumeric\ncharacters to be displayed as a label or characters to be dis-\nplayed as a label or character string. The label or string is to\nbe placed with the lower left corner of the first character at the\nlocation specified by the M, N Coordinate. There shall only be one\nM, N Coordinate pair and one set of alphanumeric characters in the\nplot data block.\n1\nThe character data within the block are to be interpreted as\nmnemonics for weather symbols to be displayed on the product.\nEach symbol is to be placed with the lower left corner of the\nsymbol at the location specified by the M,N coordinate. Each\nmnemonic will be four ASCII characters in length, left justified\nand blank filled, and the data plot block may contain any number\nof coordinates and mnemonics (511 is the maximum due to the\n4096-byte block length restriction). The weather symbol mnemonics\nand their definition are shown in Table A2-1. (Additional plot\nprocess code values may be defined at a future time to be used to\nposition characters around the M,N coordinate.)\nC2-9","ANNEX C - Section 2\nTable C2-4\nGrid Indicator (GI) Set Codes\nNOTES:\n1. Grids are defined for every regional window background map (see Table C2-2).\nThe last two digits of the GI Set Code are identical to the PI Set Code (31-49)\nfor the corresponding regional window background map. The undred digit in the\nGI Set Code gives the grid mesh (e.g., Whole Mesh = 0, 1/2 Mesh = 1, 1/8 Mesh =\n2)\n2. The array size for each GI Set Code is given in USAF AFGWC Satellite Global\nData Base mesh units (whole, half, eighth). These units can be converted to NMC\nand FNOC corresponding mesh units.\n3. Projection reference latitudes are 6ON for Northern Hemisphere polar stereo-\ngraphic and 22.5N and 22.5S for Mercator. The Mesh Lengths are true at these\nlatitudes.\n4. See AFGWC/TN - 79/003, Map Projections and Grid Systems for Meteorological\nApplications, March 1981, for a complete discussion of grid systems and their\nrelation to various map projections.\n5. Knowing the mesh size, the location of the pole on that grid mesh, and the\ngrid point of the lower left corner of the product, one can determine IPOLE/\nJPOLE as used in Mode 7/Submode 20.\nC2-10","ANNEX C - Section 2\nTable C2-4\nGrid Indicator (GI) Set Codes\nGI SET\nGRID\nCODE\nMESH\nDESCRIPTION\nARRAY SIZE\nMESH LENGTH\n031\nWhole\nCaribbean\n17 X 17\n3.71 degrees\n032\nWhole\nTropical Hawaiian\n17 x 17\n3.71 degrees longitude\nIslands\n033\nWhole\nMarianas\n17 X 17\n3.71 degrees longitude\n034\nWhole\nS. E. Asia\n17 x 17\n3.71 degrees longitude\n035-039\n(Not Assigned)\n040\nWhole\nContinental US\n17 X 17\n381 km\n041\nWhole\nEast US\n17 x 17\n381 km\n042\nWhole\nWest US\n17 x 17\n381 km\n043\nWhole\nNorth US\n17 x 17\n381 km\n044\nWhole\nCanada\n17 x 17\n381 km\n045\nWhole\nEurope\n17 X 17\n381 km\n046\nWhole\nAsia\n17 X 17\n381 km\n047\nWhole\nAlaska\n17 x 17\n381 km\n048\nWhole\nHawaii\n17 X 17\n381 km\n049\nWhole\nAzores\n17 x 17\n381 km\n050 - 130 (Not Assigned)\n131\n1/2\nCaribbean\n33 X 33\n1.86 degrees longitude\n132\n1/2\nTropical Hawaiian\n33 x 33\n1.86 degrees longitude\nIslands\n133\n1/2\nMarianas\n33 X 33\n1.86 degrees longitude\n134\n1/2\nS.E. Asia\n33 x 33\n1.86 degrees longitude\n135 - 139 (Not Assigned)\n140\n1/2\nContinental US\n33 X 33\n190.5 km\n141\n1/2\nEast US\n33 x 33\n190.5 km\nC2-11","GI SET\nGRID\nCODE\nMESH\nDESCRIPTION\nARRAY SIZE\nMESH LENGTH\n142\n1/2\nWest US\n33 X 33\n190.5 km\n143\n1/2\nNorth US\n33 X 33\n190.5 km\n144\n1/2\nCanada\n33 X 33\n190.5 km\n145\n1/2\nEurope\n33 X 33\n190.5 km\n146\n1/2\nAsia\n33 X 33\n190.5 km\n147\n1/2\nAlaska\n33 X 33\n190.5 km\n148\n1/2\nHawaii\n33 X 33\n190.5 km\n149\n1/2\nAzores\n33 X 33\n190.5 km\n150 - 230 (Not Assigned)\n231\n1/8\nCaribbean\n129 X 129\n.464 degrees longitude\n232\n1/8\nTropical Hawaiian\n129 X 129\n.464 degrees longitude\nIslands\n233\n1/8\nMarianas\n129 X 129\n.464 degrees longitude\n234\n1/8\nPhilippines\n129 X 129\n.464 degrees longitude\n235\n- 239 (Not Assigned)\n240\n1/8\nContinental US\n129 X 129\n47.62 km\n241\n1/8\nEast US\n129 X 129\n47.62 km\n242\n1/8\nWest US\n129 X 129\n47.62 km\n243\n1/8\nNorth US\n129 X 129\n47.62 km\n.\n244\n1/8\nCanada\n129 X 129\n47.62 km\n245\n1/8\nEurope\n47.62 km\n129 x 129\n246\n1/8\nAsia\n129 X 129\n47.62 km\n247\n1/8\nAlaska\n129 X 129\n47.62 km\n248\n1/8\nHawaii\n129 X 129\n47.62 km\n249\n1/8\nAzores\n129 X 129\n47.62 km\n250 - 256 (Not Assigned)\nC2-12","ANNEX C - SECTION 2\nTable C2-5\nGray Level Codes\nTo be supplied in a later issue.\nC2-13","ANNEX C, SECTION 2\nTable C2-6\nUNITS CODE (OCTAL)\nNOTES:\n*\n1.\nMultiplied by\n=\n2. **\n= Raised to the power of\n3.\n/ = Divided by or per\n4. Unit symbols shown in the symbol column are the preferred International\nStandard symbols which correspond to the Federal and American National\nstandards. Non ISO symbols correspond to practice that does not conflict with\nISO, ANSI, and Federal practice.\n5. Code units 15, 43, 46 and 74 have not been changed to conform with the\nISO, ANSI, Federal and DOD standards and practice. These will probably be\nchanged in future editions of this document to conform with metric practice.\nCODE UNITS\nSYMBOL\n°F\n0 = Degrees Fahrenheit\n1 = Degrees Kelvin\nOG\n2 = Degrees Celsius\nC\n3 = Meters\nm\n4 = Meters per Second\nm/s\n5 = Knots\nKts\n6 = Miles per Hour\nmph\n7 = Hectopascals (Millibars)\n(mbar)\nhPa\n10 = Centimeters\ncm\nm/s2\n11 = Meters per Second Squared\n(m/s**2)\n12 = Feet\nft\n13 = Geopotential Meter\nm\ngp\n14 = Seconds\nS\n2\ng.cal/cm /d (g#cal/cm**2/d)\n15 = Gram-calories per square\ncentimeter per day\n16 = Nautical Miles Per Day\nNM/ d\n17 = Centimeters per Second\ncm/s\n20 = Probability Code\n21 = Hectopascals per Second\nhPa/s\n(mbar/s)\n22 = Per Second\n1/s\n23 = Dimensionless\n24 = Percent\n%2\nm /s2\n(m**2/s)\n25 = Meters Squared per Second\n26 = Kilograms per Square Meter\nkg/mz/\n(kg/m**2)\n27 = Kilograms per Square Meter per Second\nkg/m /s\n(kg/m**2/s)\nC2-14","CODE UNITS\nSYMBOL\n30 = Hectopascals per Meter\nhPa/m\n(mbar/m)\n31 = Percent per Meter\n%/m\n32 = Degrees Kelvin per Meter\nK/m2\nW/m2\n(W/m**2)\n33 = Watts per Square Meter\n34 = Degrees Kelvin per Second\nK/s\n35 = Degrees per 10 (Compass)\n/10\n2\n(°C/10**4\n36 = Degrees Celsius per 10 Square Kilometers\nkm\n37 = Degrees (Compass Direction)\ncm2/s\n40 = Centimeters Squared per Second\n(cm**2/s)\n41 = Degrees Celsius per 100 feet (Gradient)\nC/100 ft\n42 = Degrees Celsius per 100 Km (horizontal\nC/100 km\ngradient)\n43 = Gram-Calories per Square Centimeter\ng'cal/cm (g*cal/cm**2/h)\nper hour\n44 = Refractive N Units\n45 = Meters Squared per 3 times 10 15\nm² 3 10 15\n(m**2/3*10**15)\n46 = Microbars Per Second\nubar/s\n47 = Millimeters\nmm\n50 = Kilometers\nkm\n51 = Inches\nin\n52 = Yards\nyd\n53 = Statute Miles\nmi\n54 = Nautical Miles\nNM\n55 = Degrees of Latitude or Longitude\nLat, Lon\n56 = Eights\n2\n(km**2)\n57 = Square Kilometers\nkm\nmi²\n60 = Square Statute Miles\n(mi**2)\n61 = Mean Solar Minutes\nmin\n62 = Mean Solar Hours\nh\n63 = Mean Solar Days\nd\n64 = Months\nmo\n65 = Years\nyr\n66 = Per Second times 10 to the minus\n(1/s)*10**-5\nFifth Power\n67 = Kilometers per Hour\nkm/h\n70 = Degrees of Latitude or Longitude per Day\nLat/d, Lon/d\n71 = Grams\ng\n72 = Kilograms\nkg\n3\n73 = Grams per Cubic Centimeter\n(g/cm**3)\ng/cm\n74 = Langleys\nly\n75 = Grams per Kilogram\ng/kg\n76 = Millimeters per Hour\nmm/h\n77 = Reserved\n100 = Degrees of Latitude * 100\nLat*100\n101 = Degrees of Longitude * 100\nLon*100\n102 = Number of micro-seconds\ns/(10**6)\n103 = Velocity Variance\n(cm/s)**2\n104 = Velocity\ncm/s\n1/6K\n105 = Per degree Kelvin\nC2-15","Table C2-7\nData Representation Codes\nCODE (Octal)\nDEFINITION\n0\nTwo's complement integer\n1\nIEEE Floating point\n2\nASCII (7 bit ANSI X3.4-1977)\nC2-16","ANNEX D\nPRODUCT CATALOG NUMBERS\nPage\nTable D-1 - File Indicators\nD-1\nSECTION 1 - FREE TEXT\nSECTION 2 - OBSERVATIONS (FORMATTED)\nSECTION 3 - VECTOR GRAPHICS\nSECTION 4 - SCAN LINE GRAPHICS\nSECTION 5 - DATA SETS\nSECTION 6 - DISPLAY\nSECTION 7 - MISCELLANEOUS\nD","ANNEX D\nTable D-1\nFile Indicators\nTo be supplied in a later issue.\nD-1","ANNEX E\nLOCATION IDENTIFIERS\n(Not available with this issuance)\nSECTION 1 GENERAL\nSECTION 2 METEOROLOGICAL PROGRAM\nSECTION 3 MISCELLANEOUS\nE","ANNEX F\nEXAMPLES\nNo. 1\nVECTOR GRAPHIC PRODUCT STRUCTURE\nF","ANNEX F\nEXAMPLES\n1. Vector Graphic Product Structure\nNo.\nNOTES\nMode 01, Submode 01\nProduct Identification Block\n1\nMode 04, Submode 20\nVector Graphic Product\n2\nDefinition Block\nMode 01, Submode 04\nDefine Plot Parameters Block\n3\n4\nMode 04, Submode 02\nRelative Vectors Block for\ntemperature contour 1\n4\nMode 04, Submode 02\nRelative Vectors Block for\ntemperature contour n\n5\nMode 05, Submode 03\nLine Labels Character Block\nfor temperature contours 1-n\n6\nMode 01, Submode 04\nDefine Plot Parameters Block\nMode 04, Submode 02\nRelative Vectors Block for\n7\npressure contour 1\nMode 04, Submode 02\nRelative Vectors Block for\n7\npressure contour m\n8\nMode 05, Submode 03\nLine Labels Character Block\nfor pressure contours 1-m\nMode 01, Submode 04\nDefine Plot Parameters Block\n9\nMode 04, Submode 02\nRelative Vectors Block for\n10\ncold front\nF-1","ANNEX F (cont.)\nVector Graphic Product Structure\nNOTES\nMode 05, Submode 03\nLine Labels Character Block\n11\nfor cold front\nMode 01, Submode 04\nDefine Plot Parameters Block\n12\nMode 05, Submode 06\nWind Barbs Data Plot\n13\nMode 01, Submode 04\nDefine Plot Parameters Block\n14\nMode 05, Submode 02\nData Plot Block for station\n1\n15\nMode 05, Submode 02\nData Plot Block for station 1\n15\nMode 01, Submode 04\nDefine Plot Parameters Block\n16\nMode 05, Submode 05\nWeather Symbols Block\n17\nMode 01, Submode 04\nDefine Plot Parameters Block\n18\nMode 05, Submode 01\nAlphanumeric Characters\n19\nBlock for line 1\nMode 05, Submode 01\nAlphanumeric Characters\n19\nBlock for line k\nMode 01, Submode 02\nEnd of Product Block\n20\nF-2","ANNEX F (cont.)\nVector Graphic Product Structure\nNOTES:\nIdentifies the product.\n1.\nGives product related information.\n2.\nSet up parameters for plotting temperature contours, e.g., line\n3.\ncharacter - dashed, line color - red.\n4.\nTransmits vectors defining temperature contours 1 -n.\nTransmits labels to be associated with temperature contours.\n5.\nSet up parameters for plotting pressure contours, e.g., line\n6.\ncharacter - solid, line color - blue.\nTransmits vectors defining pressure contours 1-m.\n7.\nTransmits labels to be associated with pressure contours.\n8.\nSet up parameters for plotting cold front, e.g., line character -\n9.\nsymbolic, line color - blue.\n10. Transmits vectors defining cold front line.\nTransmits labels to be associated with cold front.\n11.\n12. Set up parameters for plotting wind barbs, e.g., line character -\nreset, line color - green.\n13. Transmits wind barbs.\n14. Set up parameters for plotting station plots, e.g., line color -\norange.\n15. Transmits data plots for stations 1-1.\n16. Set up parameters for plotting weather symbols, e.g., line color\n- red.\n17. Transmits weather symbols to be plotted.\n18. Set up parameters for plotting product legend, e.g., line color -\nblack.\n19. Transmits data for product legend.\n20. Termination of product.\nF-3","ANNEX F\nEXAMPLES\nNo. 2\nAlphanumeric Product\nMODE 01 SUBMODE 01\nPRODUCT\nLENGTH\n01\nIDENTIFICATION\nPRODUCT\n001\n001\nIDENTIFICATION\nBLOCK\nK\nA\nBLOCK\nW\nN\nU\n000\nPRODUCT IDENTIFIER\n\"AA\" PLUS MANOP\nNUMBER (10 bytes)\nFILE TIME (6 bytes)\nMODE 05 SUBMODE 04\n305\n004\nMANOP HEADER\nALPHANUMERIC\nS\nA\nDATA BLOCK #1\nU\nS\n2\n4\nK\nA\nW\nN\n2\n2\n1\n2\n0\n0\nASCII CR\nASCII LF\nMESSAGE 1 SUBSET\nK\nO\nIDENTIFIER\nF\nF\nMESSAGE 1 TEXT\nASCII SPACE\nCHR 1\nCHR 2\nCHR 3\nCHR L-1\nCHR L\nASCD RS\nASCII CR\nMESSAGE 2 SUBSET\nASCII LF\nK\nIDENTIFIER\nB\nL\nV\nASCII\nSPACE\nCHR 1\nCHR 2\nEND OF TEXT FOR\nCHR M\nASCII RS\nMESSAGE K\nASCII CR\nASCII LF\nASCII ETB\nASCII\nSPACE\nNOTE: New Mode 05 Submode 04 required because next\nmessage would cause block length to exceed 4096\ncharacters.\nF-4","ANNEX F (cont.)\nAlphanumeric Product\nMODE 05 SUBMODE 04\n305\n004\nMESSAGE K+1 SUBSET\nALPHANUMERIC\nK\nB\nDATA BLOCK#2\nIDENTIFIER\nA\nB\nASCII SPACE\nCHR 1\nEND OF TEXT FOR\nCHR N\nASCII RS\nMESSAGE J\nASCII CR\nASCII LF\nASCII ETX\nASCII\nSPACE\nMODE 01 SUBMODE 02\n301\n002\nEND OF PRODUCT\nBLOCK\nF-5","ANNEX F\nEXAMPLES\nNo. 3 Surface Formatted Binary Product\nMODE 01 SUBMODE 01\n01 . LENGTH\nPRODUCT\n001\n001\nIDENTIFICATION\nK\nG\nBLOCK\nW\nc\nU\n000\nG\nF\nS\nA\nU\nS\n0\n1\nBLANK\nE.i\nLANK\n1982\n2\n5\n12\n00\nMODE 03 SUBMODE 21\n01 LENGTH\nFORMATTED BINARY\n003\n021\nDATA DESCRIPTION\nFIXED DATA\nK=# OF\n# OF BYTES\nBLOCK\nDESCRIPTORS\nELEMENTS\nIN ELEMENT\nPER SET\nSET\nM = # OF ELEMENT SETS\nELEMENT #1\n=\nA\nDESCRIPTION\nL\nBLANK\n4\n4\n0\n23 (octal)\n0\n0\n0\nELEMENT #2\nP\nP\nDESCRIPTOR\nP\nBLANK\n10 (octal)\n2\n0\n7\n1\n-1\n0\nELEMENT #K\nW\nW\nDESCRIPTOR\n1\nBLANK\nSTART BYTE\n2\n0\n23 (octal)\n0\n0\n0\nF-6","ANNEX F (cont )\nSurface Formatted Binary Product\nMODE 03 SUBMODE 01\n01\nLENGTH\nFORMATTED BINARY\n003\n001\nELEMENT 1 FOR\nDATA BLOCK #1\nK\nB\nSTATION 1\nL\nV\nELEMENT 2\n10241\n.\nELEMENT K\n17\nELEMENT 1 FOR\nK\nB\nSTATION 2\no\nS\n.\nELEMENT 2\n10113\ne\nELEMENT K\n00\nELEMENT 1 FOR\nK\n0\nSTATION N\nF\nF\nELEMENT 2\n10264\na\nELEMENT K\n93\n1\nNOTE: New Mode 03 Submode 01 required because next\nset of data would cause block length to exceed 4096\nbytes.\nMODE 03 SUBMODE 01\n01\nLENGTH\nFORMATTED BINARY\n003\n001\nDATA BLOCK #2\nELEMENT 1 FOR\nK\nS\nSTATION N+1\nT\nL\nELEMENT 2\n10245\nELEMENT K\n17\nF-7","ANNEX F (cont.)\nSurface Formatted Binary Product\nELEMENT 1 FOR\nK\no\nSTATION M\nK\nC\nELEMENT 2\n10151\nELEMENT K\n00\n!MODE 01 SUBMODE 02\n301\n002\nEND OF PRODUCT\nBLOCK\nF-8","ANNEX F\nEXAMPLES\nNo.\n4 Upper Air Formatted Binary Product\nMODE 01 SUBMODE 01\n01\nLENGTH\nPRODUCT\n001\n001\nIDENTIFICATION\nK\nG\nW\nC\nBLOCK\nU\n000\nG\nF\nU\nW\nU\nS\n0\n4\nBLANK\nBLANK\n1982\n6\n20\n12\n00\nMODE 03 SUBMODE 20\n01 LENGTH\nFORMATTED BINARY\n3\n20\nPRODUCT DEFINITION\nBLANK\nBLANK\nBLOCK\nBLANK\nBLANK\n72\n202\nMODE 03 SUBMODE 21\nFIXED DESCRIPTORS\n01\nLENGTH\nFORMATTED BINARY\n003\n021\nDATA DESCRIPTION\n6\n10\nBLOCK\n40\nELEMENT #1\nP\nR\nDESCRIPTION\nS\nBLANK\n4\n2\n0\n7\n1\n0\n0\nELEMENT #2\nG\nP\nDESCRIPTION\nH\nBLANK\n6\n2\n0\n13 (octal)\n1\n1\n0\nELEMENT #3\nT\nM\nDESCRIPTION\nP\nBLANK\n8\n2\n0\n2\n1\n-1\n0\nELEMENT #4\nD\nP\nDESC RIPTION\nD\nBLANK\n10\n2\n0\n2\nF-9","ANNEX F (cont.)\nUpper Air Formatted Binary Product\n1\n-1\n0\nELEMENT #5\nS\nP\nDESCRIPTION\nD\nBLANK\n12\n1\n0\n5\n1\n0\n0\nELEMENT #6\nD\nI\nDESCRIPTION\nR\nBLAN:\n13\n1\n0\n37 (octal)\n1\nI\n0\nMODE 03 SUBMODE 0\n01\nLENGTH\nFORMATTED BINARY\n003\n001\nLEVEL 1\nDATA BLOCK\n980\n0\n215\n25\n8\n27\nLEVEL 2\n900\n80\n182\n50\n15\n30\nLEVEL 40\n100\n1620\n-400\n(all binary ones)\n85\n03\n01\nLENGTH\nMODE 03 SUBMODE 2.\nFORMATTED BINARY\nREPORTED\n003\n021\nSIGNIFICANT\n3\n6\nDATA DESCRIPTION\nLEVEL DATA\n1\nBLOCK\nM\nW\n1\nBLANK\nF-10","ANNEX F (cont.)\nUpper Air Formatted Binary Product\n4\n2\n0\n13 (octal)\n1\n1\n0\nT\nP\n1\nBLANK\n6\n2\n0\n13 (octal)\n1\n1\n0\nP\nP\nW\nBLANK\n8\n2\n0\n51 (octal)\n1\n-2\n0\nMODE 03 SUBMODE 01\n01\nLENGTH\nFORMATTED BINARY\n003\n001\nDATA BLOCK\nELEM # 1\n885\nELEM #2\n1176\nELEM #3\n255\n1\nMODE 01 SUBMODE 02\n301\n002\nEND OF PRODUCT\nBLOCK\nF-11","ANNEX F\nEXAMPLES\nNo. 5 Unpacked Gridded Data Product\nMODE 01 SUBMODE 01\nD1\nLENGTH\nPRODUCT\n001\n001\nIDENTIFICATION\nK\nG\nBLOCK\nW\nC\n\"\n000\nG\nX\nP\nG\nN\nA\n4\n5\nI\nA\nFILE TIME (6 bytes)\nMODE 07 SUBMODE 20\n01\nLENGTH\nGRIDDED\n007\n020\nPRODUCT\n011\n141\nSCALE FACTOR\nDEFINITION\nBLOCK\n001\n002\nZERO FILLED\nZERO FILLED\nZERO FILLED\nZERO FILLED\nNUMBER OF COLUMNS (M)\nNUMBER OF ROWS (L)\nREFERENCE I COORDINATE\nREFERENCE J COORDINATE\nBEGIN VALID PERIOD\n(four bvtes)\nEND VALID PERIOD\n(four bytes)\nIPOLE\nJPOLE\nRE:D\nLONGITUDE X\n002\n002\nMODE 3 SUBMODE 21\n01\nLENGTH\nFORMATTED BINARY\n003\n021\n& UNPACKED UGDF\n001\n002\n8 OF ELEMENT SETS (MxL)\nDATA\nT\nM\nDESCRIPTION\nP\nBLANK\nBLOCK\n1\n004\n002\nZERO FILLEDI\n002\n001\n-001\n000\nMODE 3 SUBMODE 01\nLENGTH\n01\n001\nFORMATTED BINARY\n003\nTEMP FOR POINT 1(1)/3(1)\n& UNPACKED UGDF\nTEMP FOR POINT 1(2)/J(1)\nDATA\nTEMP FOR POINT I(N)/J(K)\nF-12","ANNEX F (cont.)\nUnpacked Gridded Data Product\nMODE 03 SUBMODE 01\n01\nLENGTH\nFORMATTED BINARY\n003\n001\n& UNPACKED UGDF\nTEMP FOR POINT I(N+1)/J(K)\nDATA BLOCK 2\nMODE 03 SUBMODE 01\nFORMATTED BINARY\n& UNPACKED UGDF\nDATA BLOCK M\nTEMP FOR POINT I(M)/J(L)\nMODE 01 SUBMODE 02\nEND OF PRODUCT\nBLOCK\n*U.S. GOVERNMENT PRINTING OFFICE : 1987. 181-100:62471\nF-13","WORKING GROUP FOR AUTOMATED WEATHER INFORMATION SYSTEMS\nMR. LOUIS J. BOEZI, Chairman\nDR. WILLIAM T. SOMMERS\nDepartment of Commerce, NWS\nDepartment of Agriculture, USFS\nLT COL KENNETH P. FREEMAN\nDR. STEPHAN A. NELSON\nDepartment of Defense, USAF/AWS\nNational Science Foundation\nMR. STANLEY A. CHREST\nDR. JOHN THEON\nDepartment of Defense, USAF/ESD\nNational Aeronautics and Space\nAdministration\nMR. GENE JENSEN\nDepartment of Transportation, FAA\nMR. JOHN L. MCKIE\nDepartment of Defense, USN/FNOC\nMR. BOB BETCHER\nDepartment of Defense, CNOC\nMR. ROBERT T. JASKE\nFederal Energy Management Administration\nMR. DAVID LUECK\nDepartment of Defense, USA\nMR. OWEN WILLIAMS\nDepartment of Interior, USGS\nH. DALE SELLHEIM, Secretary\nOffice of the Federal Coordinator for Meteorology\nDepartment of Commerce\nTASK GROUP FOR COMMUNICATIONS INTERFACES AND DATA EXCHANGES\nMR. JAMES G. HOWCRAFT, Chairman\nLT. COL. DAVID A. LEATHERWOOD\nDepartment of Commerce, NWS\nDepartment of Defense, AWS\nMR. JERRY BAKER\nMR. JOHN L. MCKIE\nDepartment of Transportation, FAA\nDepartment of Defense, USN/FNOC\nMS. EVELYN GOINS\nMR. DONALD CAVINESS\nDepartment of Defense, USAF/CCSO\nDepartment of Defense, AFGWC\nMR. ROGER A. DAVIS\nMR. REGINALD B. LAWRENCE\nDepartment of Commerce, NOAA/NWS\nDepartment of Commerce, NOAA//NESDIS\nLENA LOMAN, Secretary\nDepartment of Commerce, NOAA/NWS"]}