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：2003
卷号：XXXIV-3/W13
出版社：Copernicus Publications
摘要：The new Dutch national digital elevation model (AHN), acquired with laser altimetry, is almost complete. Local water boards want to use the laser data for water management tasks such as determining permitted water levels within draining areas and measuring land subsidence rates. In most parts of the Netherlands the precision of the AHN is sufficient for this purpose. However, in peat meadow areas the precision demands are higher because these areas are more susceptible to land subsidence. In these areas the mean field heights of water management entities of about 100 ha up to 700 ha have to be measured with cm-precision. Comparing traditional terrestrial methods (DGPS, tachymetry) with laser altimetry showed that the precision of the AHN does not suffice for mean field height determination in peat meadow areas. However, formerly performed block design analysis showed that adding more ground control points and extra cross strips in a 1D strip adjustment can improve the height precision of a laser altimetry elevation model. The demanded precision seemed to be achievable with those extra ground control points. In order to verify these theoretical results, a practical test was performed. The former introduced error description scheme for laser altimetry data is used to quantify the different error components and to propagate them to the precisions of mean field heights. However, the improvement of the height precision is less than expected. This is mainly caused by strip deformations due to long term positioning errors of GPS/INS. Nevertheless, the results of the pilot are useful to determine future laser altimetry block configurations taking into account the precision demands of the users. An example for weighing benefits against costs is given
