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UAV flight missions • System solutions • Remote sensing • Aerial mapping • Geoinformation
UAV Services

Mapping

With our UAV-Mapping technology we fly an aerial mapping mission of e.g. 1 km² within 30 minutes or less while maintaining very high image overlaps along track, e.g. 80 %, and across track, e.g. 70% or more. Depending on the task often the GPS-survey of 3D ground control points (GCPs) is conducted while the UAV Flight Mission (Link zu: “UAV Flight Mission”) is under way. Use of our RTK-GPS-technology helps reducing GCPs but does not eliminate GCPs, as they can be used not only for georeferencing and quality control, but as well for camera field calibration.

The subsequent, computational digital surface model (DSM) reconstruction is based on image processing methods. Here, one extracts from georeferenced aerial images via image matching procedures multiple-identical 3D surface-points. This is done for all aerial images constituting the (super-)block of UAV-imagery and delivers as interim-result an extremely dense 3D-point-cloud, often 100 Million points and more. The obtained point-cloud accurately models very fine-grain surface structures of half a meter or less spatial resolution.

 

 

Contrary to this approach, terrestrial surveying delivers a few thousand accurate and well placed 3D points being used to form a triangle-based digital surface model, also called TIN = triangular irregular network. Fine-grain surface structures are usually not included in a TIN and thus have to be captured in an extra effort if required.

Miscellaneous filter algorithms help sorting and reducing the enormous 3D point-cloud down to a still very dense DSM of e.g. ≤ 50 cm of square raster spacing, while determining for each 3D raster-point its accuracy, a feature usually not available in the TIN approach. Fine-grain structures such as e.g. singular truck-dumps, wash-outs, or local ridges are via photogrammetry automatically 3D-modelled using the UAV-Mapping approach. Achievable height accuracies are in dependency of the ground sampling distance (GSD) resp. flying height above ground level (AGL). They are in the magnitude of 0.8 to 1.5 GSD. Planimetric accuracy is in the magnitude of 0.5 GSD.