Some problems of realization spaceborne SAR in P, UHF, VHF bands

Assessment of wavelengths in range from 70 cm up to 3 m is one of actual directions in space-based SAR development. However, the low-frequency systems have serious difficulties with producing a spatial resolution about few meters. The resolution of a low-frequency SAR is affected by: a) the SAR hardware channel non-linearity; b) distribution of troposphere and ionosphere refraction factor; c) fluctuations of atmosphere refraction factor. This article discusses these theoretical problems.