A Fast Full-Wave Data Generation Method for Bistatic Subsurface SAR

This papers presents a fast full-wave method for generating data in bistatic subsurface SAR. The method considers a fix transmitter, a fixed target and a moving receiver that samples the scattered field. The method works by illuminating the target by the transmitter (in the absence of the receiver) and saving the resultant current distribution on the surface of the target. After that, the receiver is excited (in the absence of the target and the transmitter) and its field in the lower half space is saved. Reciprocity is then used to relate the voltage across the receiver terminals to the target current distribution and the field in the lower half space due to the receiver. Following this approach leads to a reduction in data generation time by a factor of $N/2$ where $N$ is the number of the samples required in the SAR simulation. The proposed method is evaluated by comparing the data it generates with the data generated by the brute-force full numerical approach.