Ultra-Wide-Swath SAR Imaging Enabled by Multiple-Elevation-Beam F-Scan with Two-Burst ScanSAR

Abstract

This article presents a comprehensive study of a novel synthetic aperture radar (SAR) technique designed for ultra-wide-swath imaging with high azimuth resolution. It provides a thorough explanation of the concept, design, and performance prediction of the proposed mode. The unambiguous imaging of the wide swath is enabled by using frequency scanning (F-Scan) with multiple simultaneous elevation beams. The resulting blind ranges are solved by employing a two-burst ScanSAR approach. The key guiding design principle is to achieve homogeneous performance across the scene, without prioritizing one direction or region over the others. For this purpose, the main techniques applied are the processing of a variable power beamwidth (PBW), the use of nonlinear chirps, and the transmission of subpulses. These methods ensure an equalized ground range resolution and noise-equivalent sigma-zero (NESZ) in range. The novel mode is shown to achieve both ultra-wide swaths up to 500 km, high azimuth resolution, and also very high image quality.