FMCW SAR Raw Signal Simulator for Extended Scenes

Abstract:
With the compact size, light weight and low cost, Frequency-Modulated Continuous wave (FMCW) Synthetic Aperture Radar (SAR) systems are gaining more and more attention for earth observation and space detection where frequent revisits at low cost are needed or small size is required. Therefore, a FMCW SAR raw signal simulator is highly demanded to quantitatively support the design of a FMCW SAR, to help mission planning, to test processing algorithms, and to analyze jamming and noises. In this paper, an efficient and precise FMCW SAR raw signal simulator is developed in the two-Dimensional (2D) frequency domain. By taking advantage of Fast Fourier Transform (FFT), the proposed raw signal simulation approach highly reduces the computational load with respect to the time domain approach. Furthermore, the range frequency conversion will precisely simulate the variation of the range–azimuth coupling. Range Doppler Algorithm (RDA) is used to focus the conceived raw signal. Finally, the electromagnetic imaging with Physical Optics (PO) method is used to validate the proposed simulation approach.