Fast simulation of SAR raw data from complex scenes

摘要

In the analysis of SAR, there is a need of simulating complex scenes without having measured radar raw data available. The common method is based on a set of point reflectors, which model the response from an extended target. The received I,Q-signals along the SAR aperture are computed, and the effects of internal noise and uncompensated phase errors are easily included. This method becomes extremely cumbersome for complex scenes with radar response from each resolution cell. In this paper, a much more rapid method of raw data generation is applied. The complex numbers representing the SAR image are then converted to radar raw data using the SAR-processing algorithms backwards. The key transform is the scene centre focusing, which ties together SAR data and sensor geometry. This method of generating raw data is several orders of magnitude faster than the direct method described above. The effects of internal noise and phase errors, due to imperfect motion compensation, can easily be included. The method can be applied as well to simulation studies of auto-focusing, DPCA and STAP.