Moraine coverage type glacier recognition method combining polarization decomposition and topographic features

Abstract

The invention relates to a moraine coverage type glacier recognition method combining polarization decomposition and topographic features. Firstly, a coherence matrix T is calculated according to a radar scattering matrix S; polarization decomposition characteristics, local incident angles and included angles delta between radar beams and the slope direction are obtained through polarization decomposition and geocoding, principal components of the multiple polarization decomposition characteristics are analyzed and then combined with the local incident angles to form an image to be classified,and vector files of a small (S) area, a medium (M) area and a large (L) area are obtained through segmentation of delta by taking 60 degrees as a unit. Secondly, the optical image is segmented to obtain a ground class sample vector, and the to-be-classified image is cut to calculate a sample value; and finally, an SVM classification algorithm is executed on the to-be-classified images, and the moraine coverage type glacier is identified. Compared with a traditional method, polarization decomposition characteristics used in the method are closely related to physical attributes of the glacier surface, classification is executed in a partitioned mode, mistaken classification caused by terrains can be effectively weakened, glacier area classification is further refined, and the recognition precision is further improved.

Description

technical field [0001] The invention relates to a method for identifying a moraine-covered glacier on a SAR image based on polarization decomposition characteristics and angle information between a radar beam and a slope aspect, and belongs to the technical field of remote sensing geoscience applications. Background technique [0002] As the world's climate continues to change and extreme weather occurs frequently, people are paying more and more attention to the impact of climate on the cryosphere on Earth, especially glaciers, which are important indicators of climate change. Using remote sensing to identify glaciers is of great significance for understanding glacier resources and analyzing global climate change. However, optical images are restricted by weather conditions, and the glacier area is covered by clouds most of the year, and optical images can only identify part of the clean glaciers, and thermal infrared images are also affected by clouds. The mechanism of gl...

AI Technical Summary

Problems solved by technology

However, optical images are restricted by weather conditions, and the glacier area is covered by clouds for most of the year, and optical images can only identify part of the clean glaciers, thermal infrared images will also be affected by clouds

The mechanism of glacier recognition by optical images is the reflection of solar radiation on the surface of the glacier, but the phenomenon of different objects with the same spectrum and the same object with different spectra can easily lead to misclassification of glacier regions, especially the spectral characteristics of moraine-covered glaciers are similar to those of rocks

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