Multi-pass SAR coherent change detection method based on general likelihood ratio

Abstract

The invention discloses a multi-pass SAR coherent change detection method based on a general likelihood ratio. The multi-pass SAR coherent change detection method includes the steps that S1, multi-pass SAR image pairs are selected and recorded as {f1, f2,..,fk}; S2, multi-pass SAR image pixel pairs are selected; S3, maximum likelihood estimation is carried out on a covariance matrix; S4, likelihood ratio hypothesis testing is carried out; S5, the multi-pass SAR image pixel pairs are sequentially selected, and the step S4 is repeated to obtain a change detection result. The multi-pass SAR coherent change detection method assumes that complex pixels corresponding to an SAR imaging area changing in the multiple image collecting stage and complex pixels corresponding to the SAR imaging area not changing in the multiple image collecting stage follow different circular symmetry complex Gaussian distributions respectively, the covariance matrix of the circular symmetry complex Gaussian distributions in the assumption is estimated, then detection statistics is determined and compared with a threshold, whether the two assumptions succeed or not is checked, namely whether the imaging area changes or not is detected, the tiny changes can be detected, and the changing process can be observed.

Description

technical field [0001] The invention belongs to the technical field of synthetic aperture radar (SAR), in particular to a multi-pass SAR coherent change detection method based on generalized likelihood ratio. Background technique [0002] Change detection technology can be widely used in monitoring changes in forest vegetation, soil moisture, and snow cover; monitoring changes in crop growth and land cover; monitoring changes before and after various disasters, such as earthquake area positioning and disaster assessment; monitoring Movement of sea ice, movement of mountain glaciers and landslide movement; dynamic monitoring of military target areas, battlefield strike assessment, etc. However, it is difficult to obtain change information through optical images under severe weather conditions such as clouds and fog. Since SAR is an all-day and all-weather modern high-resolution microwave remote sensing imaging radar, it can provide powerful support for decision-making in the...

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Problems solved by technology

[0005] The purpose of the present invention is to overcome the problem that the change detection probability is low or no change can be detected due to the use of only the amplitude information and the SAR image information of the two passes in the two-pass non-coherent change detection method, and to provide a method for assuming that the SAR imaging area is in multiple The corresponding complex pixel pairs obey different circular symmetric complex Gaussian distributions when there are changes and no changes during image acquisition, and then determine the detection statistics and compare them with the threshold to test whether the above two assumptions are true or not. A Ratio-based Coherent Change Detection Method for Multi-pass SAR

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