An Automatic Point Target Interpolation and Profile Extraction Method based on SAR Spectrum Image

Interpolation of point target and profile extraction of side lobe direction are the key steps of SAR image evaluation. Based on the correspondence between time domain and frequency domain features of SAR point targets, this paper proposes an interpolation and profile extraction method based on spectral image of point targets. Firstly, a complete spectrum is obtained by image segmentation of the extended spectrum, and then corner detection is performed on the extracted spectrum. Finally, the frequency domain zeros are added to the extracted spectral image to achieve time-domain interpolation, and the angle of sidelobe expansion direction is calculated according to the corner detection results for two-dimensional section extraction in time domain. In this paper, the proposed method is used to interpolate and extract the point targets under various SAR imaging geometry conditions, such as High squint SAR, spotligth SAR, sliding spotligth SAR, and GEOSAR. The experimental results verify the accuracy and applicability of the proposed method.