The paper “Investigation of systematic depth measurement errors in UAV-based laser bathymetry”, prepared by Roland Schwarz, RIEGL Senior Engineer Software Development, together with project partners from the Vienna University of Technology, was awarded the Photogrammetry Prize of the German Society for Photogrammetry, Remote Sensing and Geoinformation e.V. for the best contribution to the 2024 conference proceedings at the DGPF Annual Conference in Remagen.

In recent years, UAV-based laser bathymetry has been established as an efficient measurement method for the 3D mapping of the shallow water zone of relatively clear water bodies with high spatial resolution. The achievable penetration depth of more than twice the Secchi depth often tends to be greater than with classic, aircraft-based laser bathymetry. Systematic depth deviations from independent reference measurements have, however, been repeatedly observed, with a tendency to overestimate the water depth. It is suspected that the observed effects are related to water turbidity, which means that unrealistically large refraction coefficients > n=1.4 would have to be used to compensate for the deviations in the course of refraction correction. An experiment was carried out under controlled measurement conditions in the hydraulic engineering laboratory of the Vienna University of Technology in order to empirically prove the suspected correlation with turbidity.

The full article has been published in the proceedings of the 44th Annual Scientific and Technical Conference of the German Society for Photogrammetry, Remote Sensing and Geoinformation (March 13-14, 2024, Remagen, Germany) and can be accessed on the DGPF website (conference book). For your convenience we have prepared an English summary which is available here.