Angular Ambiguity Function and Resolution Analysis for Multichannel Radar Forward-Looking Imaging

With multiple channels in azimuth receiving echoes, multichannel radar has the potential for forward-looking imaging, and various schemes can be formulated. However, due to the different resources utilized by different imaging schemes, the angular resolution will be different. How to analyze the angular resolution and then design appropriate parameters is a key issue in multichannel radar forward-looking imaging. In this article, based on the echo model of forward-looking imaging, the imaging schemes of synthetic aperture and real aperture are illustrated first. Then, based on the ambiguity function (AF) theory, the angular AFs (AAFs) and the analytical expressions of the angular resolution for different imaging schemes are derived and analyzed. Finally, the simulation results of point targets and extended targets are presented to verify the effectiveness of the theoretical analysis, which would lay a significant foundation for the design of forward-looking imaging schemes of multichannel radar.