Terrain and visibility
Working with elevation: contour lines, analytical hillshade, slope and aspect, and the line-of-sight area from a point. The elevation source is Copernicus DEM GLO-30 with an SRTM fallback. Where no elevation tile covers the area the tool returns an empty result with the reason instead of inventing terrain.
Tools in this group: 6
Contour lines
contour
Builds elevation contours from a DEM through GDAL ContourGenerate; the interval runs from 5 to 500 m, 20 m by default. If no DEM is available for the area, an empty result is returned with the reason stated.
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Hillshade
hillshadeAnalytical hillshade from a DEM: light azimuth 0–360° (315 by default) and altitude above the horizon 0–90° (45). The result is a GeoTIFF; with no DEM for the area — an empty result with the reason stated.
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Slope and aspect
slopeComputes slope in degrees or the aspect of the slope from a DEM (the output parameter). The result is a GeoTIFF; with no DEM for the area — an empty result with the reason stated.
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Viewshed
viewshedA line-of-sight computation from an observer point over a DEM: observer height 1–100 m (2 by default), radius 100–10,000 m (1000). The result is a GeoTIFF where the visible cells are marked with the value 255.
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Clicking the map sets a point: Point.
Elevation profile along a track
elevation_profileSamples our DEM along an uploaded GPX track: ascent and descent with a smoothing threshold (10 m by default), gradients, points for a chart, CSV and a GPX with ele filled in. The only tool of the section with a form on the site; stretches with no DEM coverage or outside land are named in the response in words rather than filled with invented elevations.
Elevation above sea level at a point
point_elevation
Elevation in metres above sea level for a point or a batch of points — up to 100 per request; with no coordinates the centre of the bounding box is taken. Every point names the dataset its elevation came from, the years of acquisition and the resolution. There are no tiles over water, so elevation there is treated as zero; a read that failed is marked no_data rather than filled with an invented number.
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Clicking the map sets a point: points.
Input, output and limits
The input is a rectangular bounding box in WGS84 plus one of nine data layers; some tools also take a point. The output is GeoJSON, JSON metrics or a GeoTIFF.
| Layer | What it holds |
|---|---|
| buildings | buildings |
| roads | roads and streets |
| poi | points of interest: services, shops, tourism |
| water | water bodies |
| green_areas | green areas: parks, forests, lawns |
| railways | railways |
| boundaries | administrative boundaries |
| landuse | land use |
| waterways | waterways |
Every tool in the section is free. The bounding box may cover up to 100 km². Rate limits are 10 requests per minute per tool run and 30 requests per minute for reading the catalogue. Without signing in you get up to 10 successful calculations a day; after that the service asks you to register and answers 402 with the code login_required. A box larger than the allowed area is also 402, and an unknown tool id is 404.