Alternativas económicas para la determinación de la exactitud altimétrica de MDE obtenidas mediante técnicas LiDAR

Abstract

 Land surveying and geodesic observations evolve at the same pace as the technolo- gy they use. Nowadays, airborne LiDAR measurements have turned into one of the most popular measurement methods. In DEM created by airborne LiDAR data, the height accuracy depends on a several amount of factors. With the appropriate analysis of all error sources in LiDAR measurements, final product’s accuracy could be estimated. The influence of terrain slope and land covers are taken into account in every height accuracy assessment project for DEM generated by LiDAR techniques. But even more important is the accuracy assessment control, which is made by comparing the height data obtained by LiDAR for some control points. These points could exist previously to the work or should be measured for the occa- sion by other techniques. The quality of the DEM accuracy assessment control depends on which control points are used. In this paper the pros and cons of using some points or others for the accuracy estimation of DEM generated by LiDAR techniques are studied. There are three points kinds studied: high accuracy control points measured by GNSS on the field, survey marks previously materialized and DEM generated by classic photogrammetric methodology. The last two are far from the usual procedure and they optimize the control expenses. In the calculation, in- terpolation methods are used, therefore, the influence in the DEM accuracy of one method or other is studied. Putting the errors into tests of normality shows that they do not have this distribution due to the presence of outliers, so the use of robust statistics for the representation of the accuracy is recommended.