摘要
In order to better support Antarctic inland ice sheet expedition from Zhongshan Station to Dome A,the topographic data are necessary.At present,although the entire Antarctic DEM provided by RAMP(Ra-darsat Antarctic Mapping Project) was estimated at the highest horizontal(spatial) resolution of about 200 m,the real horizontal resolution of the DEM varies from place to place depending on the density and scale of the original source data.For ice shelves and the inland ice sheet,the horizontal resolution is about 5 km;the vertical accuracy is estimated to be ±50 m in interior East Antarctic ice sheet and away from the mountain ranges.Therefore,more accurate topographic data are unavailable in Antarc-tica.In order to meet the requirements of high-accuracy topographic information for further researches,this paper mainly addresses a fusion study of ASTER stereo pairs and ICESat/GLAS altimetry data for extraction of high-accuracy DEM in East Antarctica,based on the high horizontal resolution(15 m) of ASTER and vertical accuracy(13.8 cm) of ICESat/GLAS.First,some altimetry data were selected as vertical control points to reduce errors of image correlation matching during the extraction of ASTER-based DEM.Second,ice sheet altimetry data derived from ICESat were used to generate DEM ranging from 75° to 81°S because existing ASTER data do not cover this area and high density of the coverage of ICESat altimetry data.Finally,the DEM in coverage of the expedition route was produced.The analysis of result reveals that the DEM accuracy is improved significantly.The absolute vertical accuracy of DEM is higher than 15 m in some cases and higher than 30 m for all the areas along the expedition route except from the 009-001 scene;the interior accuracy is higher than 15 m and higher than 7 m in some cases.It can meet the requirements of topographic map at 1:50000 scale,which is an economic and advantageous method to produce the topographic products.
In order to better support Antarctic inland ice sheet expedition from Zhongshan Station to Dome A, the topographic data are necessary. At present, although the entire Antarctic DEM provided by RAMP (Radarsat Antarctic Mapping Project) was estimated at the highest horizontal (spatial) resolution of about 200 m, the real horizontal resolution of the DEM varies from place to place depending on the density and scale of the original source data. For ice shelves and the inland ice sheet, the horizontal resolution is about 5 km; the vertical accuracy is estimated to be ±50 m in interior East Antarctic ice sheet and away from the mountain ranges. Therefore, more accurate topographic data are unavailable in Antarctica. In order to meet the requirements of high-accuracy topographic information for further researches, this paper mainly addresses a fusion study of ASTER stereo pairs and ICESat/GLAS altimetry data for extraction of high-accuracy DEM in East Antarctica, based on the high horizontal resolution (15 m) of ASTER and vertical accuracy (13.8 cm) of ICESat/GLAS. First, some altimetry data were selected as vertical control points to reduce errors of image correlation matching during the extraction of ASTER-based DEM. Second, ice sheet altimetry data derived from ICESat were used to generate DEM ranging from 75° to 81°S because existing ASTER data do not cover this area and high density of the coverage of ICESat altimetry data. Finally, the DEM in coverage of the expedition route was produced. The analysis of result reveals that the DEM accuracy is improved significantly. The absolute vertical accuracy of DEM is higher than 15 m in some cases and higher than 30 m for all the areas along the expedition route except from the 009-001 scene; the interior accuracy is higher than 15 m and higher than 7 m in some cases. It can meet the requirements of topographic map at 1:50000 scale, which is an economic and advantageous method to produce the topographic products.
作者
E DongChen1,3,SHEN Qiang2,XU Ying1,3 & CHEN Gang4 1 Chinese Antarctic Center of Surveying and Mapping,Wuhan University,Wuhan 430079,China
2 Institute of Seismology China Earthquake Administration,Wuhan 430071,China
3 Key Laboratory of Polar Surveying and Mapping,State Bureau of Surveying and Mapping,Wuhan University,Wuhan 430079,China
4 Department of Geography,University of Calgary,Calgary,Alberta T2N 1N4,Canada
基金
Supported by National Natural Science Foundation (Grant No. 40606002)
Surveying and Mapping in Chinese Antarctic Expedition Area (Grant No. 1469990711109-1)
National Key Technology R & D Program (Grant No. 2006BAD18B01)
GLA12 dataset of ICESat/GLAS in National Snow and Ice Data Center (NSIDC)
