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Introduction to the report on geodesy
Author(s) -
Williams Owen W.
Publication year - 1979
Publication title -
reviews of geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 8.087
H-Index - 156
eISSN - 1944-9208
pISSN - 8755-1209
DOI - 10.1029/rg017i006p01352
Subject(s) - geodesy , altimeter , geoid , geodetic datum , satellite laser ranging , geology , satellite , remote sensing , very long baseline interferometry , satellite geodesy , geophysics , laser ranging , aerospace engineering , laser , physics , engineering , optics , measured depth
The achievements of the U.S. geodetic community during the years 1974–1978 between the General Assemblies of the IUGG are summarized in this section. During this quadrennium, American geodesy dramatically moved from the era of primarily meeting the traditional needs of surveying and mapping into one of supporting a broad spectrum of geophysical and planetary disciplines. This movement was aided by modern technology epitomized by the increases in Doppler satellite observations, multifrequency distance measurements, lunar and satellite laser ranging, very long base line interferometry (VLBI), satellite altimetry measurements and inertial positioning. By far the most spectacular achievement in the field of geodesy during this period was the global sampling of sea surface topography with precision radar altimeters aboard the National Aeronautics and Space Administration (NASA) GEOS‐3 and Seasat‐1 satellites. The GEOS‐3 altimetry data set, acquired over a 3‐year period (1975–78), significantly improved our knowledge of the global gravity field of the earth, the oceanic geoid and the related mean gravity anomalies. Had the Seasat‐1 not failed after 3 months, an even more detailed knowledge of the oceanic geoid would be available today. Even with this early demise, Seasat‐1 in 3 months collected more altimetry data with greater accuracy than did GEOS‐3 in 3 years.