Phase Synchronization of Distributed Array Radar based on Minimum Entropy Method

Distributed array radar (DAR) coherently fuse multiple small-aperture subarrays, achieving equivalent resolution of a large aperture, which enables significant benefits for automotive driving, remote sensing and other applications. However, individual oscillators and coarse synchronization system induced phase deviation breaks the array spatial uniform sampling. To address this problem, a minimization entropy based DAR phase synchronization method is proposed to fuse the measurements of multiple subarrays. First we establish an connection between phase deviations and the uncertainty of spatial spectrum shape through information entropy. Then phase deviation required for synchronization is estimated by iteratively optimizing the entropy value to minimum. Simulations demonstrate the effectiveness of the proposed method and indicate that phase corrected DAR possesses high noise suppression and high angular resolution.