Satellite altimetry

The present status of the instrumentation and applications of satellite altimetry are reviewed. The earth-orbiting altimeters launched thus far are all basically conventional monostatic tracking radars which make three fundamental measurements: (1) time of arrival (altitude), (2) shape (waveform sample gates), and (3) amplitude (automatic gain control). A comparison of the fundamental characteristics of the present altimeter systems is given, along with evaluation of the preliminary results of altimeter data collected by Seasat-1. The application results described are mainly from the analysis of approximately 1/3 of the 2000 hours of altimeter data obtained from GEOS-3 through October 1978.