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南极数字高程模型(DEM)是从事南极地学和环境变化研究的基础.内插是建立数字高程模型的重要技术点,插值方法有多种,根据不同的适用情况,不同的插值方法各有优劣.利用克里格、距离反权、三角网剖分、最小曲率以及移动平均5种插值方法分别建立南极冰盖小范围区域的DEM,通过抽取部分观测数据作为验证值对各插值方法进行了比较.结果表明:克里格插值方法的可靠性最好,稳定性最高.然后,利用克里格插值方法,基于ICESat测高卫星的GLA12数据建立了南极冰盖的DEM.由于南极大陆实测数据有限,缺乏对DEM的检核.为了分析所建DEM的可靠性,利用中国南极内陆冰盖考察所采集的GPS实测数据,对所建立的DEM进行了验证分析.结果显示,DEM在坡度较缓的南极内陆冰盖区域精度较高,符合度在3 m以内;距离卫星轨道越近的区域精度越高,可达到1 m以内.在坡度较大,高程变化较为显著的区域如沿海地区,精度较低,差距最大的点超过40 m.
The Antarctic Digital Elevation Model (DEM) is the basis for the study of Antarctic geosciences and environmental change.Important interpolation is an important technical point in the establishment of digital elevation model, there are many interpolation methods, different interpolation methods have advantages and disadvantages according to different applicable situations Using the Kriging, the DEM of the Antarctic ice sheet in a small area was established by using five kinds of interpolation methods: inverse weight, triangulation, minimum curvature and moving average method respectively, and the interpolation methods were compared by extracting some of the observed data as verification values The results show that the Krieger interpolation method has the best reliability and stability, and then uses the Kriging interpolation method to establish the DEM of the Antarctic ice sheet based on the GLA12 data of the ICESat altimetry satellite.As the measured data of the Antarctic continent is limited , The lack of a check on the DEM.In order to analyze the reliability of the built DEM, the use of China Antarctic inland ice cover survey collected GPS measured data to verify the DEM established.The results show that the DEM is relatively slow The precision of the Antarctic inland ice sheet region is high, with a conformance within 3 m, and the closer to the satellite orbit, the higher the accuracy of the region can be within 1 m. The coastal areas such as low precision, the point of maximum gap exceeds 40 m.