Lidar 2019 — Relevé 3D from Luxembourg territory

The data under this heading is derived from a three-dimensional aerial survey based on Light Detection and Ranging (LiDAR) technology. The flight was carried out in February 2019 with a density of 15 points per square metre and a horizontal accuracy of ± 3 cm and vertical accuracy of ± 6 cm. The density (15 points/m²) indicates the pulses sent from the system. The measured density may be higher, depending on the type of the scanned surface (single reflection/multiple reflection). The cadastre and topography administration provides a web viewer based on “potree” technology (potree.org) that allows online consultation of the point cloud. This tool allows the visualisation of the cloud of colored points (orthophoto and classification) as well as the extraction of coordinates or measurements. For more information, please see the demo emptying of this tool: https://www.youtube.com/watch?v=f2x088mU7wQ&t=135s **Point cloud — Data structure** The raw data are structured as tiles with a spatial extent of 500 m x 500 m and contain on average between 5 and 7 million measured points. To simplify data downloading raw tiles have been grouped into compressed files (zip) with up to 9 raw tiles (representing a spatial extent of 1 500 m x 1 500 m). The assembly board — zip files provides an overview of the combined tiles and the assembly board — dot clouds contains the link between raw tiles and the compressed file. A visualisation of the assembly tables is available on map.geoportail.lu, also allowing a graphic selection of a tile to be downloaded. [Display tiles at map.geoportail.lu](https://map.geoportail.lu/theme/main?version=3&zoom=15&X=682116&Y=6377849&lang=fr&layers=1788&opacities=0.75&bgLayer=orthogr_2013_global&crosshair=false) A python script is available for an automated download of all tiles in this dataset. **Attention**: For a download of all tiles it is necessary to provide a free hard disk capacity of ± 500 GB). The script requires in the installed python environment and an indication of the API key (available in details of the data.public.lu login). **Point cloud — point classification** The point cloud is made available in 9 different categories: [0] — Unclassified items [2] — Soil [3] — Low vegetation [4] — Average vegetation [5] — High vegetation [6] — Buildings [7] — Low Points (noise) [9] — Water [13] — Bridges, Gateways, Viaducs [15] — High voltage lines Number indicates the class identifier.