Coherent Ground Mapping of Polar Format Images with Applications to High-Resolution Wide-Area SAR Imaging

In this article, we consider some approaches to using the polar format algorithm for high-resolution wide-area synthetic aperture radar (SAR) imaging. We will broadly discuss two general approaches to extending the polar format algorithm to produce focused high-resolution imagery over wide areas. First, we will describe a fast backprojection-like algorithm based on coherently mapping polar formatted subapertures to the ground and coherently combining the ground-mapped images. Second, we will discuss an alternative approach to generating high-resolution wide-area imagery, which starts with an initial polar format image and then subsequently refines the image in subpatches in a coherently consistent manner across the image. Central to both methods is a general framework for coherently mapping polar format images to the ground.