The Subaperture Secondary Range Compression Algorithm for near space squint SAR

This paper discusses squint synthetic aperture radar (SAR) imaging in the near space platform and proposes an improved Secondary Range Compression (SRC) Algorithm, Subaperture Secondary Range Compression (SSRC) Algorithm. The key step is to use the subaperture approach in the SRC algorithm. First, the original signals are divided into subapertures in the azimuth direction of the time domain to image independently, and then the sub-bands of the frequency domain are combined to form the final SAR image. The method reduces coupling in the range and azimuth direction of the echo signal under the squint imaging mode, and addresses the problems of squint SAR in near space including overlong synthetic aperture and motion error. Simulation through point targets demonstrates the improvement in azimuth resolution, ISLR and PSLR, which verifies the effectiveness of this proposed SSRC algorithm in near space squint SAR imaging.