基于星载激光雷达和雷达高度计数据的南极冰盖表面高程制图

发布时间：2018-06-16 17:56

本文选题：南极冰盖 + 数字高程模型　；参考：《遥感学报》2014年01期

【摘要】：南极数字高程模型DEMs(Digital Elevation Models)是研究极区大气环流模式,南极冰盖动态变化和南极科学考察非常重要的基础数据。目前,科学家已经发布了五种不同的南极数字表面高程模型。这些数据都是由卫星雷达高度计,激光雷达和部分地面实测数据等制作而成。尽管如此,由于海洋与冰盖交接的南极冰盖边缘区随时间的快速变化,有必要根据新的卫星数据及时更新南极冰盖表面高程数据。因此,我们利用雷达高度计数据(Envisat RA-2)和激光雷达数据(ICESat/GLAS)制作了最新的南极冰盖高程数据。为提高ICESat/GLAS数据的精度,本文采用了五种不同的质量控制指标对GLAS数据进行处理,滤除了8.36%的不合格数据。这五种质量控制指标分别针对卫星定位误差、大气前向散射、饱和度及云的影响。同时,对Envisat RA-2数据进行干湿对流层纠正、电离层纠正、固体潮汐纠正和极潮纠正。针对两种不同的测高数据,提出了一种基于Envisat RA-2和GLAS数据光斑脚印几何相交的高程相对纠正方法,即通过分析GLAS脚印点与Envisat RA-2数据中心点重叠的点对,建立这些相交点对的高度差(GLAS-RA-2)与表征地形起伏的粗糙度之间的相关关系,对具有稳定相关关系的点对进行Envisat RA-2数据的相对纠正。通过分析南极冰盖不同区域的测高点密度,确定最终DEM的分辨率为1000 m。考虑到南极普里兹湾和内陆地区的差异性,将南极冰盖分为16个区,利用半方差分析确定最佳插值模型和参数,采用克吕金插值方法生成了1000 m分辨率的南极冰盖高程数据。利用两种机载激光雷达数据和我国多次南极科考实测的GPS数据对新的南极DEM进行了验证。结果显示,新的DEM与实测数据的差值范围为3.21—27.84 m,其误差分布与坡度密切关系。与国际上发布的南极DEM数据相比,新的DEM在坡度较大地区和快速变化的冰盖边缘地区精度有较大改进。
[Abstract]:The Antarctic Digital elevation Model (DEMsN Digital elevation models) is an important basic data for the study of the polar atmospheric circulation model, the dynamic changes of the Antarctic ice sheet and the Antarctic scientific survey. So far, scientists have published five different digital surface elevation models for Antarctica. These data are made from satellite radar altimeter, lidar and some ground measured data. However it is necessary to update the surface elevation data of the Antarctic ice sheet according to the new satellite data due to the rapid change of the Antarctic ice sheet edge area between the ocean and the ice sheet. Therefore, we have produced the latest Antarctic ice cover elevation data using radar altimeter data Envisat RA-2) and lidar data (ICESat-GLASS). In order to improve the accuracy of ICEsat / GLAS data, five different quality control indexes are used to process the GLAS data, and 8.36% of the unqualified data are filtered out. The five quality control indexes are aimed at satellite positioning error, atmospheric forward scattering, saturation and cloud effect. At the same time, dry and wet troposphere correction, ionospheric correction, solid tide correction and polar tide correction are performed on Envisat RA-2 data. For two different altimetry data, a relative elevation correction method based on the geometric intersection of spot footprints based on Envisat RA-2 and GLAS data is proposed, that is, by analyzing the overlap point pairs between GLAS footprint points and Envisat RA-2 data center points. The correlation between the height difference of these intersecting points (GLAS-RA-2) and the roughness representing the topographic fluctuation is established, and the relative correction of the Envisat RA-2 data is carried out for the point pairs with stable correlation. The resolution of the final Dem is 1000 m by analyzing the density of the measured high points in different regions of the Antarctic ice sheet. Considering the difference between the Prydz Bay and the inland area, the Antarctic ice sheet is divided into 16 regions. The best interpolation model and parameters are determined by semi-variance analysis, and the 1000 m resolution Antarctic ice sheet elevation data are generated by using the Klukin interpolation method. The new Antarctic Dem is validated by two kinds of airborne lidar data and GPS data obtained from many Antarctic scientific surveys in China. The results show that the difference between the new Dem and the measured data is 3.21-27.84 m.The error distribution is closely related to the slope. Compared with the Antarctic Dem data published internationally, the accuracy of the new Dem is greatly improved in the areas with high slope and rapidly changing ice sheet edge.
【作者单位】：中国科学院遥感与数字地球研究所遥感科学国家重点实验室;北京师范大学全球变化与地球系统科学研究院;清华大学地球系统科学研究中心;
【基金】：国家高技术研究发展计划(863计划)(编号:2008AA121702) 国家重点基础研究发展计划(973计划)(编号:2012CB957704) 国家海洋局极地科学重点实验室开放基金(编号:KP2008006)~~
【分类号】：TN957.52

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