Noise suppression method used for synthetic aperture radar image of city region

Abstract

The invention discloses a noise suppression method used for a synthetic aperture radar (SAR) image of a city region. The method comprises the following steps of estimating Alpha-Stable distribution parameters for sample data in sliding windows on real part / imaginary part data of the SAR image, and recording the parameters of all the sliding windows; performing logarithmic transformation on amplitude data of the SAR image, defining sliding windows corresponding to a real part / an imagery part on the image subjected to the logarithmic transformation, and calculating an Alpha-Stable distribution expression and a noise distribution expression in each corresponding window; calculating a posterior probability of a product of the Alpha-Stable distribution expression and the noise distribution expression, and taking the value of a maximum posterior probability in a dynamic range as the value of a central pixel of the sliding window; and performing exponential transformation on the values of the central pixels of all the sliding windows subjected to maximum posterior estimation, thereby obtaining a filtered amplitude image. According to the technical scheme, speckle noises of the SAR image of the city region are suppressed more effectively, so that the quality of the SAR image is improved.

Description

technical field [0001] The invention relates to a noise suppression method for a synthetic aperture radar image, in particular to a noise suppression method for a synthetic aperture radar image in an urban area. Background technique [0002] Synthetic Aperture Radar (SAR) works all-weather and all-weather, which makes SAR remote sensing play an increasingly important role in the fields of solid earth science, ecological science, hydrology science and marine science. Especially with the acceleration of urbanization in recent years, synthetic aperture radar plays an increasingly important role in remote sensing applications by virtue of its imaging advantages. However, speckle noise in SAR images, especially speckle noise in urban areas, has been perplexing the processing and interpretation of SAR images. [0003] In the past few decades, many SAR image speckle noise suppression methods have been proposed, which can be roughly divided into two categories: multi-view processin...

AI Technical Summary

Problems solved by technology

However, in order to improve the radiation resolution, the multi-look processing ignores different information, such as the change of the radar scattering cross section with the observation angle or the influence of space changes, and the resolution of the image will be reduced.

Post-imaging processing technology SAR image speckle noise suppression method, the coherent speckle suppression algorithm based on spatial domain filtering technology is the mainstream, based on the maximum a posteriori probability (Maximum a posteriori, referred to as MAP), the noise is suppressed to a certain extent, the image Edge information is rarely lost, and no false edges are generated, but this method is not suitable for SAR image regions with different properties (uniform area, non-uniform area and isolated point)

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