Comparison and analysis of CryoSat DEM and the several Antarctic DEM

Abstract

Antarctica is covered by huge snow and ice, and its geological structure is bounded by the Trans-Antarctic Mountains, and is generally divided into the East Antarctic Shield and the West Antarctic Active Zone. Digital elevation model (DEM) is one of the important basic data to study the Antarctic ice sheet change. Obtaining elevation change information through the comparison of multi-period DEM is an important means to analyze the changes in the thickness and material balance of the Antarctic ice sheet. However, the horizontal and vertical errors between different types of DEM affect the accuracy of the analysis results. In this study, the horizontal error first eliminated by registration between DEMs, then elevation difference and standard deviation are calculated between CryoSat DEM and other DEMs, finally the temporal and spatial variation characteristics are evaluated. The results show that in the plane, the horizontal offset between TanDEM_X DEM and CryoSat DEM is the smallest, while that between ICESat DEM and CryoSat DEM is the largest. In the vertical direction, within the gradient range of 0° ~ 1°, the mean elevation difference between CryoSat DEM and TanDEM_X DEM is between 3.5 and 5.5 m, and the standard deviation is less than 18.0 m. The mean elevation difference between CryoSat DEM and Bamber 1km DEM is between -2.5 and +1.0 m, and the standard deviation is less than 24.2 m. The mean elevation difference between CryoSat DEM and ICESat DEM is between -25.0 and -1.0 m, and the standard deviation is less than 47.2 m. The mean elevation difference between CryoSat DEM and RAMPv2 DEM is between 1.3 and 3.2 m, and the standard deviation is less than 45.6 m. It is found that the internal elevation of Antarctic ice sheet increases, but the elevation of southwest ice sheet and southeast ice sheet decreases, and the southwest pole decreases obviously, while the elevation of Antarctic edge area decreases obviously. This study provides an important reference for global change research and Antarctic material balance research.

Keywords

• antarctic
• geological structure
• digital elevation model
• horizontal error
• elevation difference