Glacial surface topography and its changes in the Western Qilian Mountains derived from TanDEM-X Bi-Static InSAR

High-precision glacier Digital Elevation Model (DEM) and accurate glacier elevation changes is very important for the research of glacier mass balance and glacial dynamics over mountain glaciers. Here, we present a bi-static InSAR processing algorithm for DEM generation with TanDEMX-X(TDX)/TerraSAR-X(TSX) data and SRTM DEM in the western Qilian Mountains. First of all, a 10 m resolution of TDX DEM is calculated and evaluated as 1.493 ± 0.747 m. Moreover, the glacier elevation changes of the western Qilian Mountains between 2000 yr and 2013 yr are estimated, which are in the negative state as a whole from 2000 yr to 2013 yr. This study demonstrates the great potential of the TanDEM-X bi-static InSAR technology in mapping glacier surface topography and estimating glacier elevation changes over mountain glaciers.