Practical Methods for the Verification of Countrywide Terrain and Surface Models

The Swiss Federal Office of Topography is leading a project for the determination of correct agricultural surfaces. As a part of this project, a Digital Terrain Model and a Digital Surface Model is being generated using airborne laser scanning methods. These two models must achieve a height accuracy of 50cm and a mean density of 1 point per m. One of the main tasks of swisstopo is to control the quality of the two models. To fulfil this task, a combined strategy using global and local control techniques has been established. This paper will focus on the philosophy and the tools swisstopo uses for the verification of a countrywide produced elevation model. Our investigations showed that quality control is mandatory when generating models by means of airborne laser scanning.