High resolution dual channel receiving SAR compensation technique

This paper presents the theory of dual-channel receiving Synthetic Aperture Radar (SAR) and internal calibration. Using the data of an airborne high resolution SAR demonstrate System collected in May 2006, the internal calibration error and amplitude & phase errors are analyzed. The raw data is compensated by internal calibration data to improve range compression quality compared to auto-focus method compensation. The image of synthesized dual channel data is performed. With the internal calibration and the dual-channel amplitude & initial phase errors compensation, the quality of SAR image can be improved dramatically.

1. Introduction

In Synthetic Aperture Radar [1] (SAR) system, single-transmitter and dual-channel receiving operational mode is adopted to obtain large swath as well as to obtain high resolution in the cross-range direction. Especially in satellite based SAR system, for instance, Radarsat-2 made in Canada is taken this technique as a backup mode to overcome the limitation between large swath and high resolution. Internal calibration can be used to compensate channel error effectively. So the effect of range compression can be improved greatly.