A multi-directional SAR imaging mode for change detection based on phased array radar

In this paper, a simultaneous multi-directional SAR imaging mode is investigated, which is utilized to obtain multitemporal SAR images of the same area for change detection. After the echoes are collected by phased array radar with multiple beams pointing to different directions, they are separated in Doppler frequency domain and used to image respectively. Design method of the antenna pattern is presented, the relationship between the pattern and the array structure is analyzed, and some criteria are achieved. In order to ensure that the echoes spectrums are nonaliasing, an optimum pulse repeated frequency is selected based on the analysis of each beam signal signature in detail. The change rule of the azimuth resolution varying with the beam direction is analyzed and compared with the mechanical rotational radar. Numerical simulation results validate the analysis.