Derivation and Validation of the Echo Waveform for the Chinese Tiangong-2 Interferometric Imaging Radar Altimeter

Abstract

We introduce the derivation and validation of the echo waveform model (EWM) for the ChineseTiangong-2 interferometric imaging radar altimeter (TG2-InIRA), which was launched on Sept. 152016. The TG2-InIRA adopts small incident angles from 1 to 8 degree and short interferometric baseline of 2.3m so as to realize high coherency measurement of radar scattering from sea surface aiming to retrieve three- dimensional ocean topography with centimeter-level accuracy. We derived the EWM by multiplication of the antenna pattern in range direction, the backscattering coefficient model and the system response function. Real in-orbit observation data has been used to validate the developed EWM and an initial wind speed retrieval algorithm is proposed.