Spatial Resolution Improvement via Radar Parameter Adjustment for Extremely-High-Squint Spotlight SAR

The extremely-high-squint spotlight synthetic aperture radar (SAR) has been widely used in military and commercial fields. Due to the extremely-high-squint angle, the point spread function (PSF) used for SAR resolution evaluation suffers from severe distortion and thus results in non-uniform spatial resolution. To solve this problems, this paper proposes a novel radar parameter adjustment (RPA) method to correct the PSF distortion during the data acquisition. The mechanism is to achieve an orthogonal PSF by correcting the wavenumber spectrum distortion. In this case, the radar parameters, i.e., the center frequency and the chirp rate, vary at every azimuth sampling position. The proposed approach is validated via the computer simulations.