Bistatic imaging method for GEOSAR in the strip mode and UAVSAR in the TOPS mode

For bistatic synthetic aperture radar (SAR) of the geosynchronous transmitter in the strip mode and the unmanned aerial vehicle (UAV) receiver in the terrain observation by progressive scans (TOPS) mode (GEO-UAV BiSAR), a new imaging method is proposed. Firstly, the slant range model is inferred by Taylor expansion, and the point target two-dimensional frequency spectrum with the space-variant in range through series reversion is further presented. Then, under the condition of the small pulse repetition frequency, the bistatic imaging method is proposed for the azimuth frequency aliasing caused by the steering of the antenna beam. In this imaging processing, the dechirp technology is firstly used to solve the above aliasing, and then subsequent imaging operations are carried out, i. e. range compression, range migration correction, azimuth compression and dechirp processing. Finally, simulations validate the imaging method.