The Importance of Understanding Error in Lidar Digital Elevation Models

The paper presents the results of an accuracy analysis of a number of gridded Digital Surface Models (DSMs) which have been created from first return laser scanning (LiDAR) data. DSMs are created using a variety of methods, and differences between the models and the raw LiDAR data are quantified and the spatial patterns of the errors explored. The results presented in this paper demonstrate the importance of understanding not only the global accuracy of elevation models, but also the location and magnitude of individual errors which are created during DSM creation. Results to date indicate that errors of up to 1m can be created by using different techniques, and that these errors will affect the results of any subsequent analysis. This investigation highlights the importance for both data suppliers and data users to better understand errors which are created within digital elevation models and incorporated within any subsequent analysis.