Control leveling

Details

• Personal Author:
  Whalen, Charles T.
• Corporate Authors:
  National Geodetic Survey (U.S.)
• NOAA Program & Office:
  NOS (National Ocean Service) ; NGS (Office of National Geodetic Survey)
• Description:
  Control leveling is used to determine precise elevations of bench marks (monumented points) above or below a reference surface called a datum. The National Geodetic Survey (NGS) of the ; National Ocean Survey (NOS), formerly the U. S. Coast and Geodetic Survey (USC&GS), now a component of the National Oceanic and Atmospheric Administration, determines elevations in meters above or below the National Geodetic Vertical Datum of 1929. ; Bench marks are located at distances of about 1.6 km along railroads and highways in the United States to form level lines. These level lines form a net of closed loops. The present program for ; development of the fundamental vertical control net calls for first-order lines at approximately 160-km intervals with a subdivision of second-order lines spaced at 40 to 80 km. In certain areas of intense development, the net is again subdivided by second-order lines spaced at 8 to 16 km. The current net consists of 370,000 km of first- and second-order leveling.
• Series:
  NOAA technical report NOS NGS ; 73-8
• Format:
  PDF
• Document Type:
  Technical Report
• License:
  https://creativecommons.org/publicdomain/zero/1.0/
• Rights Information:
  CC0 Public Domain
• Compliance:
  Library
• Download URL:
  https://repository.library.noaa.gov/view/noaa/30816/noaa_30816_DS1.pdf
• File Type:
  [PDF - 62.86 MB]
• Collection(s):
  National Ocean Service (NOS)
• Main Document Checksum:
  urn:sha-512:2de17a14e95ae5a6b34ce8320f6e05168feff57b40e16d89503ab70ea10b7a6420d9d9a1b2075a2f460796e95bfe8303d0869f8170efb62e8e3c9fef87bbeb2a