首页 > , Vol. , Issue () : 1993-2002
The method of extracting glacier by remote sensing has important value of scientific research and application The threshold segmentation method has high efficiency and accuracy in remote sensing feature extraction. But in terms of threshold selection, traditional manual selection threshold is low automation, repeated trial operation, and easy to be affected by subjective factors. For example, the normalized snow cover index can effectively separate the glacier information from the background information, However, the threshold is almost always found manually, which is easily affected by subjective factors. Therefore, it is necessary to develop an effective method to automatically calculate the glacier extraction threshold. Gaussian Mixture Model (GMM) is established for Normalized Difference Snow Index (NDSI) of local glacier region by the expected maximum algorithm, and remove the mixed pixel meta classes in the region. Then, the GMM was used to simulate the NDSI distribution of purified glacier and non-glacier. According to the distribution of the improved gaussian mixture model, the glacier extraction threshold was calculated automatically in the region. Three regions at different altitudes were experimented. And then the boundary extraction of Karlik mountain glacier in hami, xinjiang was compared with the glacier inventory data, and good extraction results were obtained. The experimental results show that the threshold values calculated by different grids in the same experimental area are slightly different, while the threshold values calculated by different grids in different experimental areas are largely different, which also indicates that the algorithm is still stable in the regions with large differences. That also explains that the results of glacier extraction threshold calculated by this method are reliable, accurate and stable in different regions. The study result shows that this method solves the problem of unbalanced proportion of glacier and non-glacier in GMM curve simulation to some extent, and the automatic calculation results of glacier extraction threshold are reliable, accurate and stable in the regions with large differences. This GMM method is available for certain application of delineating glacier boundary in remote sensing.