Interpolation method for geometric correction in highly squint synthetic aperture radar

In this study, a two-dimensional (2D) sinc interpolation method is proposed to carry out the geometric correction in highly squint synthetic aperture radar (SAR). The point spread function (PSF) has 2D non-perpendicular sidelobes in highly squint SAR. This kind of sidelobes may result in the folded skewed spectrum. The conventional interpolation methods cannot do the geometric correction for slant range images with the folded skewed spectrum. A new 2D sinc kernel is designed according to PSF's non-perpendicular sidelobes, in order to circumvent the problem mentioned above. The new kernel has the same sidelobe direction as the PSF. And then two coefficients are introduced to obtain ground range images with large pixel spacing, which can avoid under-sampling and eliminate the resolution's space-variation. The proposed method is verified by computer simulation and SAR real data processing.