Snow mapping with SIR-C mulpolarization SAR in Tienshan Mountain

The areas covered by snow and glacial ice are important parameters in climatological and hydrological investigations, particularly in alpine regions. The most common use of remote sensing in snow studies is to monitoring snow-covered area to measure the change as an index in a snowmelt runoff model. Active microwave sensors can discriminate snow and glacier from other surfaces in all weather conditions. The radar polarization signature of an object permits a more accurate description of the object of interest than single-polarization measurements. The authors´ study is intended to aid the examination of the usage of multi-frequency mulpolarization SAR data to map snow- and glacier-cover in the Tienshan Mountains. The results showed that C-band VV/HH images can discriminate between wet-snow and snow-free areas with an accuracy of 83-87%. Some difficult is found in discriminating glacier ice from snow and rock. L-band HH/VV images can separate snow-cover areas from other targets with an accuracy of 89-93% but there are problems in the discrimination between rock and snow, and the cross-polarization SAR images can be used to solve this problem. Multifrequency mulpolarization SAR data are shown to be useful for snow-cover mapping in alpine areas