Imaging Region Bound of Scanning Radar Angular Super-resolution on Motion Platform

Airborne radar can observe a wide-region image with coarse resolution using a scanning antenna. Because the aperture size of the antenna on a motion platform is limited, super-resolution imaging methods based on different echo models are presented to improve its angular resolution. In this paper, the applicable scopes of the super-resolution imaging models are compared quantitatively. First, the traditional models of scanning radar, such as the approximate convolution model (ACM) and the complex phase-convolution model (CPM), are introduced, and we analyze the echo models in spatial frequency domain. Then, according to the comparison of the spatial bandwidth of the antenna pattern and that of the platform motion, the strict region bound and the relax region bound for scanning radar are analyzed. At last, the numerical region bounds are deduced to analyze the influencing factors. The bounds are significant for the working mode design and imaging method selection for a scanning radar. Simulations verify the analyzed region bound.