Theoretical Analysis of Circular-Scanning SAR Based on Resolution and Imaging Efficiency Comparison

Circular-scanning Synthetic Aperture Radar (SAR) can quickly generate vast maps of earth's surface, providing precise positioning information by scene-matching approach. Although it has gained more attention to improve the imaging method, the quantitative comparison of the theory performance, between circular-scanning SAR and other classical imaging SAR mode, is obliviously performed in previous work. Based on the terminal-guidance parameter of aerocraft, we compare azimuth resolution among circular-scanning SAR, circular-scanning Doppler Beam Sharpening (DBS) and stripmap SAR. The computational complexity and imaging area are calculated during one scan cycle of the three modes. Simulation results show that, the azimuth resolution of circular-scanning SAR is better and more stable than that of the circular-scanning DBS, and, the computational complexity in unit area of circular-scanning SAR is less than that of the stripmap SAR. Circular-scanning SAR is proved more practical for missile positioning and precise guidance.