"This Catalog is the second in the series planned by World Data Center A (WDC-A) for Solar-Terrestrial Physics to cover in considerable detail the data disciplines in Solar-Terrestrial Physics to cover in Considerable detail the data disciplines in Solar-Terrestrial Physics singly or in groups. It intends to cover all the data known to exist for ionospheric vertical soundings, the discipline listed as B.1 in the ICSU Guide to International Data Exchange through the World Data Centeres. In contrast to earlier catalogs which have always begun with data for the International Geophysical Year, 1957-58, the present catalog includes all known data since the beginning of systematic multifrequency ionospheric soundings; the earliest data set is 1930. This includes all the relevant data held at the data center and in direct or indirect information on data held elsewhere"--Introduction.

National Environmental Satellite and Data Information Service (NESDIS)