The report covers finding target coordinates using different kinds of digital geographic data and describes a demonstrator and a trial. A central question has been to compare the uncertainty of target coordinates between different elevation data. As a side effect, the impact on the uncertainty related to target type, location and target observation as well as the subjects' ability to locate the correct position has also been highlighted. The trial has been carried out in an office environment based on data from measurements on real targets in a real environment. The target objects have consisted of buildings and a vehicle with varying locations. The elevation models that have been the subject of comparison consist of a surface model based on laser data over Sweden and TREx DEM, which is a global elevation model based on radar measurements from satellites. The results indicate that for the vehicle in open terrain the uncertainty of the target coordinates is mainly affected by the user's ability to locate and pinpoint the correct position rather than by the choice of elevation data. For other types of terrain, the situation is unclear. The elevation difference between the surface model and the TREx DEM varies with the nature of the terrain and thus also the contribution to the uncertainty. The contribution from the user may also vary. For buildings, the elevation uncertainty is affected by the elevation models and the planar uncertainty mainly by the user's designation of the target position. Planar uncertainty is normally small as buildings are visible in the orthophoto used and can therefore be easily located and pointed out.