An Imaging Processing Method for Coprime Sampling Spaceborne SAR

Abstract

The invention discloses an imaging processing method for a coprime sampling satellite borne SAR, which belongs to the field of signal processing. The imaging processing method comprises the followingsteps: after obtaining imaging parameters, echo data and a coprime sampling matrix, firstly carrying out the range-wise pulse compression on a coprime sampling SAR echo signal, then starting from a first range gate, calculating the number of range gates spanned by the range gate echo signal according to Doppler parameters of each range gate, constructing a corresponding sparse dictionary, and intercepting a two-dimensional observation signal on the basis of the range gate echo signal, and finally reconstructing the two-dimensional observation signal by using an improved sparse reconstruction algorithm adaptive to the sparsity of the two-dimensional observation signal, thereby obtaining backscatter information of a scene target. By adopting the imaging processing method for the coprime sampling satellite borne SAR, the influence of the change of the imaging parameters along with the range door for the sparsity reconstruction can be compensated, the full-scene accurate focusing can be realized, the imaging processing under a coprime sampling working mode can be realized, the imaging accuracy is high, and the practicability is high.

Description

technical field [0001] The invention belongs to the field of signal processing, and relates to a spaceborne SAR imaging processing method, in particular to an imaging processing method for coprime sampling spaceborne SAR. Background technique [0002] Synthetic Aperture Radar (SAR) is an active microwave imaging sensor. By transmitting broadband signals and combining synthetic aperture technology, it can simultaneously obtain high-resolution images in the direction of range and azimuth, and realize the remote control of the target area. Distance Active Imaging. Compared with traditional optical remote sensing and hyperspectral remote sensing, SAR has all-weather, all-time, high-resolution earth observation capabilities, and has a certain penetration. technical means. [0003] Earth observation with high resolution and wide swath is one of the development trends of spaceborne SAR. For the traditional spaceborne SAR system, the azimuth spatial resolution and the range mappi...

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Problems solved by technology

[0008] The purpose of the present invention is to solve the imaging problem of spaceborne SAR under coprime sampling mode, and propose an imaging processing method for coprime sampling spaceborne SAR, which can complete the precise focusing when the distance and azimuth two-dimensional coupling cannot be ignored deal with

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