Time and Phase Synchronization Methods For Distributed Coherent Aperture Radar

Distributed aperture radar can enhance target detection performance and sensitivity through coherent operation without requiring larger radar apertures and higher transmission power. However, achieving coherent operation for distributed aperture radar is a significant challenge. In this work, we research the methods for time and phase synchronization of distributed coherent aperture radar. Firstly, we present a method of transmit coherence which establishing a likelihood function based on conditional probability and estimating the time synchronization error of each array radar by optimizing the likelihood function using analytical and iterative methods. Next, the method of receive coherence is introduced, the minimum value of the information entropy function is solved to obtain the phase synchronization error estimation of the received signal. After completing time and phase error compensation, signal coherent superposition at the target is achieved. Simulation results show that the method achieves signal coherent superposition and theoretical gain.