Delay/Doppler compensation: a new concept for radar altimetry

摘要

Abstract: This new satellite radar altimeter concept useson-board real-time partially coherent processing torealize an along-track impulse response shape andposition which are not degraded by terrain slope orelevation. The key innovation is delay compensation,analogous to range curvature correction in a burst modesynthetic aperture radar. The detected outputs of manybursts are incoherently integrated to accumulate morethan one hundred equivalent looks. The along-trackfootprint size is on the order of 200 - 300 meters. Theradar equation for the delay/Doppler radar altimeterhas an h$+($MIN@5/2)$/ dependence on height, which ismore efficient than the corresponding h$+($MIN@3)$/factor for a pulse-limited altimeter. The radiometricresponse obtained by the new approach would be 10 dBstronger than that of the TOPEX/POSEIDON altimeter, forexample, if the same hardware were used in thedelay/Doppler mode. The concept is a candidate smallsatellite instrument for earth observation, withparticular suitability for precision altimetry ofcoastal and polar ice sheets. !13