Analysis of Impact of Phase Center Variations in Linear Array Antena Downward-looking 3D-SAR Imaging

The Linear Array Downward-Looking 3D-SAR (LADL 3D-SAR) achieves the ablity of resolving imaging in three dimensions using linear array antennas. The phase center variations of linear array antennas, which is unavoidable under real condition, will lead to echo phase errors that impact the imaging of 3D-SAR. In this paper, the analyzing model of the phase center variation is firstly established, then the impact of phase errors caused by phase center variations in LADL 3D-SAR is discussed based on stochastic process orthogonal expansion.The impact on sidlobe and the statistical relationship between ISLR and the deviation of phase center variations is derived analytically. Finally, the simulation results demonstrate the effectiveness of the theoretical analysis.