Wavefront curvature compensation in PFA for spotlight bistatic SAR with arbitrary platforms paths

Abstract

Polar format algorithm (PFA) as is an efficient algorithm can be well applied to spotlight bistatic synthetic aperture radar (SAR). However, a planar wavefront assumption which leads to image distortion is made. In this study, a new method to compensate for the wavefront curvature of PFA image is presented and it can well correct the defocusing effect and geometry distortion even under arbitrary platforms paths. By projecting the coefficients of Taylor expansion from the azimuth-time domain to wavenumber domain, the new method does not need repeated interpolations to construct the compensation filters for all the errors, which can decrease computational expense in a way. Finally, the effectiveness of this method is verified by numerical simulation.

Keywords

• radar imaging
• geometry
• synthetic aperture radar
• wavefront curvature compensation
• spotlight bistatic SAR
• arbitrary platforms paths
• polar format algorithm
• bistatic synthetic aperture radar
• planar wavefront assumption
• image distortion
• PFA image
• defocusing effect
• geometry distortion
• azimuth-time domain
• compensation filters
• Taylor expansion