Enhanced SAR Image Formation via a Modified Omega-K Algorithm

In this paper, a high-resolution synthetic aperture radar (SAR) focusing technique is proposed based on a modified omega-K algorithm in case of long synthetic aperture time. The proposed algorithm includes three stages. First, a modified reference function multiply is applied to two-dimensional frequency data to perform a coarse range cell migration. Second, the residual non-stationary phase error related to a range-azimuth coupling is compensated using a range block processing after implementing the interpolation process based on a newly devised kernel function. Finally, the high-precision SAR focusing is carried out via the azimuth focusing function, which enables us to realize a range variant motion compensation. The experimental results with simulated and real measured SAR data are presented to validate the feasibility and superiority of the proposed method.