K-SVD and sparse representation based polarization SAR (synthetic aperture radar) image classification method

Abstract

The invention discloses a K-SVD and sparse representation based polarization SAR (synthetic aperture radar) image classification method and solves problems that the amount of classification categories is limited by an existing method and polarization characteristic information is not fully utilized. The method includes the steps of 1), calculating a covariance matrix by taking a polarization coherent matrix of a polarization SAR as input data; 2), extracting the coherent matrix, the covariance matrix, Ps, Pd, Pv, H, and alpha from each pixel to form a characteristic matrix; 3), selecting training samples from actual terrain distribution to form an initial dictionary; 4), training the initial dictionary with a K-SVD algorithm to obtain a training dictionary; 5), representing the characteristic matrix with the training dictionary and calculating the sparse coefficient with an OMP algorithm; 6), restructuring the characteristic matrix with the calculated sparse coefficient, and determining the categories of pixels to acquire the final classification result. Polarization characteristics of polarization SAR images are utilized, the amount of the classification categories is not limited, and the method can be applied to classification of the polarization SAR images.

Description

technical field [0001] The invention belongs to the technical field of image processing and relates to the classification of polarimetric SAR images. The method can be used for the classification and recognition of polarimetric SAR image targets. Background technique [0002] Radar is an active detection system that can work around the clock. It can penetrate a certain surface and change the frequency and intensity of emitted waves. Synthetic aperture radar technology (SAR) is a kind of imaging radar technology. It uses the relative motion of radar and target to synthesize a larger equivalent antenna aperture radar with a smaller real wireless aperture by data processing. Polarization SAR is a new type of radar used to measure echo signals. It can record the phase difference information of combined echoes in different polarization states, which greatly improves the ability to identify ground objects. Polarimetric SAR image classification is an important step in polarimetric...

AI Technical Summary

Problems solved by technology

However, due to the multi-class division and merging in Freeman decomposition, this method has high computational complexity

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