SRTM

• SRTM:

A simple library to load SRTM data and return heights in meter for a given lat/lon. Based on Alpinechough.Srtm .

Usage

// create a new srtm data instance.
// it accepts a folder to download and cache data into in addition to the source you want to use for the data.
// USGS data is immediately available, but is of a lower resolution.
var srtmData = new SRTMData(@"/path/to/data/cache", new USGSSource());
// NASA data is of a higher resolution, but requires creating an account at https://urs.earthdata.nasa.gov/users/new/.
var credentials = new NetworkCredential("username", "password");
var srtmData = new SRTMData(@"/path/to/data/cache", new NASASource(credentials));

// get elevations for some locations
int? elevation = srtmData.GetElevation(47.267222, 11.392778);
Console.WriteLine("Elevation of Innsbruck: {0}m", elevation);

elevation = srtmData.GetElevation(-16.5, -68.15);
Console.WriteLine("Elevation of La Paz: {0}m", elevation);

elevation = srtmData.GetElevation(27.702983735525862f, 85.2978515625f);
Console.WriteLine("Elevation of Kathmandu {0}m", elevation);

elevation = srtmData.GetElevation(21.030673628606102f, 105.853271484375f);
Console.WriteLine("Elevation of Ha Noi {0}m", elevation);

// if a smoother result is preferred, it is possible to use bilinear interpolation at the cost of some accuracy
double? smoothElevation = srtmData.GetElevationBilinear(47.267222, 11.392778);
Console.WriteLine("Elevation of Innsbruck: {0}m", elevation);

smoothElevation = srtmData.GetElevationBilinear(-16.5, -68.15);
Console.WriteLine("Elevation of La Paz: {0}m", elevation);

smoothElevation = srtmData.GetElevationBilinear(27.702983735525862f, 85.2978515625f);
Console.WriteLine("Elevation of Kathmandu {0}m", elevation);

smoothElevation = srtmData.GetElevationBilinear(21.030673628606102f, 105.853271484375f);
Console.WriteLine("Elevation of Ha Noi {0}m", elevation);

Data sources

We implemented two sources of data, the USGS SRTM and NASA SRTM. If you want to add an extra source, we're accepting pull requests, you just need to implement something like this.

We need help!

If you think we need to add another source of data let us know via the issues, if you know more about SRTM or of another source of elevation, also let us know.