The estimation of ocean waves parameters from image spectra obtained by different orbital altitude SAR (ERS-1 and ALMAZ-1)

The possibilities of imaging ocean waves by two satellites, ERS-1 and the Russian ALMAZ-1, are analysed. The image spectra were calculated over 6 collocated image pairs taken quasi-simultaneously. It is shown, that due to higher (approx. 2 times) ratio of slant range to satellite velocity the spectra of ERS-1 are affected by a strong azimuth cut-off compared with those of ALMAZ-1. The distortions in wave imaging grow with growing of azimuth wavenumber and of difference of R/V parameter between ERS-1 and ALMAZ-1 SAR