A Speckle Removal Method for Polarized SAR Image Based on Pseudo-PID Natural Gradient

Abstract

The invention belongs to the field of SAR image speckle noise reduction processing, and particularly relates to a polarized SAR image speckle noise reduction method based on the natural gradient of a PID. The polarized SAR image speckle noise reduction method based on the natural gradient of the PID includes the steps that n polarized SAR images collected at the same moment are converted to be a one-dimensional vector image; the one-dimensional vector image is preprocessed; iteration solution is carried out on the preprocessed image signal through a natural gradient algorithm of the PID to obtain a separation matrix, and one-dimensional signal output of each image is obtained by multiplying the image signal by a whitened signal; the images are reconstructed; a one-dimensional signal with the maximum equivalent number of looks is found out; an image with the maximum equivalent number of looks is the SAR image with reduced noise, the one-dimensional signal with the maximum equivalent number of looks is converted into a two-dimensional image, and the two-dimensional image is converted to be a gray level image with N*M pixel dots according to a two-dimension to one-dimension inverse conversion method. The method with the PID applied adjusts the separation step length of the natural gradient algorithm, so that the processing result image is clearer than that obtained according to a traditional method, and speediness is achieved.

Description

technical field [0001] The invention belongs to the field of synthetic aperture radar (Synthetic Aperture Radar, SAR) image coherent speckle denoising processing, in particular to a polarization SAR image coherent speckle denoising method based on natural gradient of pseudo-PID. Background technique [0002] Synthetic Aperture Radar (SAR) is a multi-parameter, multi-channel microwave imaging radar system that can simultaneously obtain radar images of ground scenes under different polarization combinations, providing more than single-polarization SAR can match. amount of information. It has a wide range of applications in oceanography, glaciology, and land research. It can obtain high-quality images and has the ability to work around the clock. In the past few decades, many countries have developed spaceborne and airborne SAR technology. SAR overcomes the defects of traditional radar and can obtain high-resolution images, which is very beneficial to the detection and identi...

AI Technical Summary

Problems solved by technology

Due to the coherent speckle noise phenomenon in SAR images, the readability of the images is greatly reduced, so that image interpretation and information extraction become very difficult

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