Coordinates

Order: longitude first

All mapx interfaces, TileJSON, MapLibre and GeoJSON use lon, lat (longitude, then latitude), that is east-west before north-south:

12.694,47.074      // lon,lat: Großglockner area

Many map apps and GPS devices show lat, lon instead. Swapped values end up in the Indian Ocean, not in Austria. The elevation API expects points=lon,lat;lon,lat. Leaflet takes [lat, lon] in L.latLng, MapLibre and OpenLayers [lon, lat].

EPSG:4326 and EPSG:3857

Inputs to the APIs are always WGS84 (EPSG:4326). Tiles are in Web Mercator (EPSG:3857), see Tile scheme. Clients convert between them themselves; you do not need to compute tile coordinates.

Web Mercator distances in Austria are about 50 % larger than true metres (factor 1 / cos(latitude)). Do not measure lengths and areas in EPSG:3857; use geodesic measurement or a local system such as EPSG:31287 (MGI / Austria Lambert) or EPSG:3035 (ETRS89-LAEA).

Official sources: MGI and ETRS89

The authorities’ source data uses different systems: Austrian national survey (MGI, for example Gauss-Krüger M28/M31/M34 and Lambert) and ETRS89 (for example ETRS89-LAEA, UTM). Between MGI and WGS84/ETRS89 there is a positional offset of several metres that is corrected with an official transformation grid.

mapx transforms correctly: all products are converted to WGS84 and Web Mercator with the official transformation procedure. You get layers that line up without applying a transformation yourself. When you overlay your own official data in MGI, use the transformation grid of your software (for example QGIS with the BEV grid), otherwise it shifts by a few metres.

Further reading

• Tile scheme
• Elevation and profile