A wide swath, full polarimetric, L band spaceborne SAR

The design of a space-borne synthetic aperture radar (SAR) with large swath coverage in full polarimetric mode is a challenging task in L band. The requirement for full-polarimetry involves a doubling of the PRF, reducing the available swath and making range ambiguities a serious problem, particularly for the cross polarization. This is the case of the next Argentinean constellation, SAOCOM, made of two identical L band SAR. In the paper it is proposed a design based on two innovative techniques, namely TOPSAR and split-band pulse coding (SBPC). TOPSAR allows for wide swath by revisiting different beams in a time-division approach. In this, TOPSAR is similar to ScanSAR mode, but with no artifacts like scalloping and azimuth varying clutter-to-noise ratio. The joint use of SBPC coding and TOPSAR allows for reduction of the range ambiguities that are particularly strong at the shallow incidence angles. The paper presents a full example of the overall SAR acquisition design fulfilling the demanding tasks.