ANALYSIS ON SPATIAL RESOLUTIONS OF LOW-FREQUENCY ULTRAWIDEBAND WIDE BEAMWIDTH SAR

Ultrawideband Synthetic Aperture Radar (UWB-SAR) is a high-resolution imaging radar with leaf-cluster penetration capability, which has broad application prospects in military and civilian fields. It can accurately map the terrain covered by the forest and imaging various targets hidden in forests. Compared with the conventional high-frequency narrow-band narrow-beamwidth (NBNB) SAR, the low-frequency UWB-SAR has the characteristics of large relative bandwidth and large imaging integral angle, and its imaging results will inevitably have new characteristics. Aiming at this phenomenon, this paper analyses the imaging characteristics of low-frequency ultrawideband wide beam SAR by point spread function. Firstly, the point spread function of low-frequency UWB-SAR is derived and its characteristics are analyzed. Then, the side-lobe direction and two-dimensional spatial resolution characteristics of the imaging results are analyzed according to the point spread function, and the relationship between spatial resolution, relative bandwidth and beamwidth is given by simulation.