Small-aperture imaging for high squint SAR based on modified Omega-K algorithm

Abstract

For high squint SAR small-aperture data imaging, the conventional Omega-K algorithm will confront two main problems. First, since the data support region (DSR) in the two-dimension (2-D) wavenumber domain is skew, the conventional algorithm cannot exploit the DSR efficiently enough and degrades the resolution when choosing the square region to process. Second, the small-aperture data can only offer short DSR of the azimuth position. When imaging in the azimuth distance domain, the images will result in serious blurring in azimuth direction unless padding large number of zeroes. Correspondingly, to solve such problems, the modified Omega-K algorithm contains mainly two parts, the “No-Squint” Processing, which corrects the skew DSR to maximize the selection area; And the Small-aperture data imaging processing, which enable the azimuth focus in wavenumber domain, eliminating the azimuth blurring. Experiments show the validity and effectiveness of the proposed algorithm.