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MODIS-Based Snow Cover Products, Validation, and Hydrologic Applications
Published in Ni-Bin Chang, Yang Hong, Multiscale Hydrologic Remote Sensing, 2012
An alternative to spatial filters for cloud impact reduction is the method based on snow line elevation. This approach assumes that the vertical snow cover distribution is similar within a region. Parajka et al. (2010) tested the snow line elevation method over Austria and found that this approach was remarkably robust, including for cases where only a few percentage of the pixels were cloud free. The cornerstone of this method is a reclassification of pixels assigned as clouds based on a comparison of their elevation with the mean elevation of all snow and land pixels. The assessment of the OA for cloud-free pixels was similar to the MOD10A1 product and only slightly decreased for cases when clouds covered more than 90% of Austria. When considering clouds as false classification, the decrease in cloud extent can be translated into a significantly higher mapping performance of the snow line elevation method. The overall annual accuracy ranged from 48.7% to 81.5%, depending on the cloud threshold used compared, with 38.5% for the original MOD10A1 product. A more favorable mapping performance of the snow line approach was found, especially for cases when the snow cover started to build or melt, which is documented by higher mapping accuracies in November, December, and April.
Glacier facies characterisation in transboundary West Sikkim Himalaya from TerraSAR-X; GLCM based classification approach
Published in Journal of Spatial Science, 2023
Arpan Sharma, Mousumi Gupta, Narpati Sharma
Following the Landsat mission by NASA, glacier facies characterisation using remote sensing and GIS is considered more efficient because in-field survey of all glaciers is not possible, especially in the Himalayan region. In this regard, Williams et al. (1991) used the Landsat Multispectral Scanner (MSS) and the Thematic Mapper (TM) with visible and infrared bands to characterise glacier facies in Bruarjokull, a surge-type outlet glacier in the Vatnajokull ice cap, Iceland. They identified morainal deposits, ice facies, transient snow line, slush zone, slush limit (diffuse) and snow facies (wet snow and frozen snow) through satellite imagery.