Radar altimeter for ocean remote sensing

Ocean radar altimetry is based on the electromagnetic backscattering of the ocean surface in response to a narrow pulse waveform under near normal incidence. The altimeter described is used to determine the satellite altitude over the sea surface, the significant wave height, and wind speeds. The instrument requires accuracy, implying high precision in radar measurements of the pertinent return echo parameters. Problem areas such as pull-in phase initialization and tracking phase are discussed and the adopted solution includes using two separated loops. The RF/IF unit and the signal processor are also discussed. A radar altimeter functional block diagram is given, as are error signals of range and slope discrimators and the deterministic simulation of loops operation. Finally the main parameters include a peak power of 400 W, a frequency of 13.5 GHz and an antenna gain of 40 dB.