SAR imaging method based on spatial domain support area fusion

Abstract

The invention discloses an SAR imaging method based on spatial domain support area fusion, mainly comprising the following steps: acquiring sub-aperture echo data; carrying out 2D fast Fourier transform, range matching filtering, phase compensation, expanded stolt interpolation and range pulse compression on the sub-aperture echo data, and getting range distance domain-azimuth wave number domain sub-aperture data after range pulse compression through calculation; de-chirping the range distance domain-azimuth wave number domain sub-aperture data after range pulse compression to get de-chirped range distance domain-azimuth wave number domain sub-aperture data, carrying out azimuth inverse fast Fourier transform on the de-chirped range distance domain-azimuth wave number domain sub-aperture data to get 2D position domain sub-aperture data, and calculating imaging data of each sub-aperture; and getting an azimuth focused full-aperture high-resolution SAR image.

Description

technical field [0001] The invention belongs to the technical field of SAR imaging, and in particular relates to a SAR imaging method based on fusion of space domain support regions, which is suitable for SAR imaging processing of airborne or spaceborne platforms. Background technique [0002] As an active detection tool, SAR (Synthetic Aperture Radar) can perform high-resolution microwave imaging of the observation scene, and is widely used in the field of remote sensing. It obtains high-resolution characteristics in the distance dimension by transmitting broadband signals, while the azimuth dimension uses platform Doppler information generated by motion achieves high resolution. [0003] In recent years, with the maturity and development of various imaging algorithms, while taking into account the imaging quality, real-time performance has become an essential requirement for many imaging systems. The concept of sub-aperture has solved the contradiction between imaging qual...

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Problems solved by technology

[0005] However, due to its special interpolation method, the traditional Omega-K algorithm makes azimuth focusing and decoupling complete at the same time; on the one hand, the traditional Omega-K algorithm makes it difficult to combine imaging algorithms with existing motion compensation methods; on the other hand, Azimuth coherent fusion between sub-apertures will not be possible to achieve high-resolution imaging; at the same time, the existing Omega-K algorithm is mainly aimed at full-aperture imaging. Since the azimuth data is focused in the spatial domain, it is necessary to perform azimuth fusion on the sub-aperture data. The zero padding operation to expand its support area greatly increases the amount of calculation and reduces the real-time performance of the algorithm

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