期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：2002
卷号：XXXIV-3/W4
出版社：Copernicus Publications
摘要：Researchers of NASA's GSFC are currently developing a scanning airborne photon-counting laser altimeter. This paper summarizes the creation of high resolution, precise DEMs from repeat passes of airborne laser scanning surveys to validate this new system. To study coastal erosion several sections of the Atlantic and Pacific coast have been mapped by NASA's Airborne Topographic Mapper (ATM) conical scanning altimeter. We selected two 5 km long and about 1 km wide stretches of the coast in Maryland to create precise Digital Elevation Models. One site is urban area (southern Ocean City) and the other is characterized by coastal marshes and beaches (northern Assateague Island). To obtain a dense data set, we combine laser altimetry data from 21 swaths acquired in 4 di.erent missions. Laser points over planar surfaces, such as .at roofs and parking lots were analyzed to check the the repeatibility of the measurements. The absolute accuracy of the laser scanning was assessed by comparing surfaces extracted from the laser point cloud with GPS and photogrammetry results. These studies confirm the 0.1-0.2 m vertical and submeter horizontal accuracy of the ATMsystem. At the heart of the interpolation procedure is a bilinear interpolation that determines the surface elevation at the grid posts from planes fitted through the points located within2mby2mgrid cells. Outlier observations are detected by using a robust estimator. The residual of the plane fitting and the uniformity of the distribution of the observations within the grid cells are used to assess the accuracy of the DEM. These parameters suggest an accuracy of 0.3 m or better for 90.4 % of the DEMpoints on the urban area, and 48.5 % of the points have an accuracy of 0.1 m or better. Similar accuracy is achieved on the site covered by natural vegetation on Assateague Island
关键词：DEMgeneration; outlier detection; validation site
