Delay/Doppler compensation: a new concept for radar altimetry,

摘要

Abstract: This new satellite radar altimeter concept uses on-board real-time partially coherent processing to realize an along-track impulse response shape and position which are not degraded by terrain slope or elevation. The key innovation is delay compensation, analogous to range curvature correction in a burst mode synthetic aperture radar. The detected outputs of many bursts are incoherently integrated to accumulate more than one hundred equivalent looks. The along-track footprint size is on the order of 200 - 300 meters. The radar equation for the delay/Doppler radar altimeter has an h$+($MIN@5/2)$/ dependence on height, which is more efficient than the corresponding h$+($MIN@3)$/ factor for a pulse-limited altimeter. The radiometric response obtained by the new approach would be 10 dB stronger than that of the TOPEX/POSEIDON altimeter, for example, if the same hardware were used in the delay/Doppler mode. The concept is a candidate small satellite instrument for earth observation, with particular suitability for precision altimetry of coastal and polar ice sheets. !13