星载双基地 FMCW-SAR 高分辨时域成像算法

Bistatic Synthetic Aperture Radar（SAR）has separate transmitting and receiving antennas，which endows the system with flexible structure and strong function expansion. Frequency modulated continuous wave（FMCW）SAR is widely used in air/ground SAR platform because of its low cost. Combining bistatic configuration with FMCW system，spaceborne bistatic FMCW-SAR is applied to satellite platform，which has both the advantages above and is an optional implementation method for future small satellite SAR constellation. At present，the research on bistatic FMCW-SAR high-resolution imaging mostly focuses on the air/ground platform，while there is few research on the space-based platform. Therefore，this paper proposes a high-resolution time-domain imaging processing algorithm suitable for spaceborne bistatic FMCW-SAR system，analyzes the correlation between the distance migration curve after dechirping and the speed of load movement，and proposes a distance migration curve positioning method suitable for space-based platforms，which achieves higher processing accuracy than the traditional time-domain algorithm. The effectiveness of the proposed method has been verified by computer simulation.