Data sources by country

F.1 Elevation data

The terms on this page are explained in Ch. 6: the source chain in section 6.2, the terrain model in section 6.5. The grid spacing is the edge length of one raster cell, so "1 m" means one height value per square metre. The height system defines the zero surface from which the height above sea level is measured, in Germany for example standard elevation zero (NHN).

F.1.1 Sources in the source chain

F.1.2 Elevation data by country

• automatic: PV-GlareCheck queries the elevation at each object itself while the level is switched on in the source chain.
• load official: "Load official terrain model" brings the model for an area into the project (Ch. 6.5).
• official data store, selection window: The map sheets are held, checked, on the PV-GlareCheck server. Height values and the terrain model come from there without waiting; you choose the area for the terrain model in the selection window on the map (Ch. 6.5).
• upload: You upload a file of your own (Ch. 6.7).
• Order: In Spain, "Official data" first queries the source with the finest grid spacing, and for equal spacing the more recent survey. If a point lies outside all connected regions, the next level of the source chain takes over, usually Google; the marker on the value shows this (Ch. 6, section 6.3).

F.1.3 Points specific to individual countries

Spain. Catalonia and Andalusia provide their terrain model as one file for the whole region, the Basque Country and Navarre through a map service; the app reads only the area from it. The terrain model of the Valencian Community (ICV) is held in checked map sheets of about 30 km × 20 km on the PV-GlareCheck server; elevation values and the terrain model come from there without waiting. If a map sheet for your site is missing, the next source provides the height of an object, and the value carries that source's marker (Ch. 6, section 6.4). In this case the app does not load the terrain model: the preview already stops and names the missing sheets. Please contact support. The app does not take over individual faulty cells of the source; a gap remains there, and the height at an object comes from the next source.

The Netherlands and France. AHN4 has no ground elevation under buildings and on water. The loaded model has gaps there; the app does not fill them. If an object lies in such a gap, its elevation comes from the next source in the chain; a notice states the number of points, and the marker on the value shows the source (Ch. 6, section 6.3). In France the app uses MNT LiDAR HD (0.5 m) for each square kilometre and only where it is missing the older RGE ALTI (1 m). Attribution, data date and grid spacing name the product used; as the licence requires, the attribution carries the date of the last update ("Stand"), the data date the survey.

F.1.4 Providers

Germany. The German states provide their DGM1 as open data, usually as GeoTIFF or XYZ in tiles of 1 km × 1 km on the geoportals of the authorities:

In Germany heights refer to standard elevation zero (NHN, DHHN2016), positions to ETRS89/UTM.

Austria, Switzerland, England. In Austria the Federal Office of Metrology and Surveying (BEV) provides the terrain model compiled from the states’ laser scanning flights (ALS-DGM, 1 m, CC BY 4.0), in Switzerland swisstopo provides swissALTI3D (0.5 m, free use), in England the Environment Agency provides the LIDAR Composite DTM (1 m, Open Government Licence v3.0 with attribution).

The Netherlands, Luxembourg, France.

Heights refer to NAP in the Netherlands and to NGF-IGN69 in France; the documentation of the Luxembourg model does not name the height system explicitly.

F.1.5 Spain

A nationwide terrain model with decimal heights cannot yet be retrieved automatically in Spain: MDT02 and MDT 50 cm of the IGN are only available file by file from the CNIG download centre. The app therefore connects regions that provide their model openly. Connecting MDT02 as a nationwide base is in preparation.

Heights refer everywhere to mean sea level at Alicante (orthometric heights), positions to ETRS89/UTM, zone 30, or zone 31 in Catalonia.