# Hosted elevation service

![](https://1672210197-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LSRNxaH2Ju9Flr7JhJD%2F-M3SkE47spr2HFUMsM_U%2F-M3SkIGuY6wxiLbnZO2V%2Fscreenshot-racemap.com-2020.03.27-16_32_25.png?alt=media\&token=799461f3-3e13-406e-8fec-99ba40be3adb)

The [Google elevation API](https://developers.google.com/maps/documentation/elevation/start?hl=de) provides a vertical accuracy of 30 m and there is no other open elevation service providing more accurate data available. During the development of [Predictive Tracking](https://docs.racemap.com/prediction) we noticed, that this cartographic data is not precise enough and we developed a self-hosted elevation service (vertical accuracy of 1 m), you can use for your own projects under MIT license. You either host this service yourself or just use our API.

* Mapzen terrain data: <https://registry.opendata.aws/terrain-tiles/>
* GitHub documentation and source code: <https://github.com/racemap/elevation-service#api-usage>
* hosted elevation service: <http://elevation.racemap.com/?lat=51.3&lng=12.5>

#### Working with the elevation data API

You can download portions of the data. The data is organized by latitude/longitude where each chunk is 1x1 degree. Eg. for downloading the UK data you need to know the lat/lng extent of the UK and download all the necessary files. Example:

```
aws s3 cp --no-sign-request s3://elevation-tiles-prod/skadi/N51/N51E000.hgt.gz /path/to/data/folder/N51
```

Make sure to reproduce the file structure when downloading, e.g. `./N51/N51E001.hgt.gz`. The whole dataset is just \~200GB, so maybe it is even feasible to download the whole thing.

Regarding the licensing, please check for yourself: <https://registry.opendata.aws/terrain-tiles/> & <https://www.mapzen.com/terms/>