基于CryoSat-2的东南极PANDA断面考察沿线DEM制作及精度分析

基于卫星测高数据，国际上先后发布了ICESat DEM、Bamber DEM等全南极DEM.相对于传统高度计，大轨道倾角、长重访周期的设计使CryoSat-2具有更大的数据覆盖范围以及更加密集的轨道覆盖；同时，SARIn模式的启用也提高了CryoSat-2对于南极边缘区域的监测能力.针对利用CryoSat-2数据提取DEM问题，对CroySat-2的轨迹覆盖特征、数据滤波方法、最优内插参数选取以及DEM精度验证等方面进行了探讨，并利用克里金插值法生成了东南极PANDA断面考察沿线1 km分辨率的DEM.结果表明：通过与ICESat数据对比，发现PANDA断面考察沿线DEM整体高程精度约为（1.57±3.30）m；但是，局部区域高程精度分析表明，DEM精度具有不均一性，随着坡度的增加DEM高程精度逐渐下降，高程稳定性也同时下降.

DEM generation and analysis using CryoSat-2 data along the expedition route in PANDA transection,East Antarctica

Satellite altimetry over the continental ice sheets was proven to be a valuable tool for studying the Dig-ital Elevation Model(DEM)by providing elevation measured over past decades. The polar scientists have re-leased ICESat DEM and Bamber DEM based on satellite altimeter data. Compared with the traditional altimeter, the long orbit cycle(369 days)and larger orbital inclination of CryoSat-2 can provide a larger and denser net-work of ground tracks. In addition,the SARIn model can also provide a higher-accuracy in the margin of Antarc-tica. In this paper,the method of data filtering,the interpolation parameter selection and the accuracy of DEM are discussed for the DEM. The DEM with a pixel spacing of 1 km along the PANDA expedition route of Antarc-tica is then extracted using ordinary Kriging interpolation with a search radius of 5 000 m. Toretrieve the accura-cy of the DEM for PANDA expedition route,the DEM was compared with ICESat surface elevation points gained from the laser campaigns. The accuracy assessment shows that the accuracy of the DEM is(1. 57 ± 3. 30) m. However,the analysis of local area demonstrates that the accuracy and stability of DEM decrease gradually with slope.