Installation

    npm install
    grunt

(Tests will fail after a fresh checkout, because tile e008/n53.dt0 must be added to 'examples'-folder.)

Usage of Terrain

var dted = require('lethexa-dted');

var fetcher = new dted.FileSystemTileFetcher('./dted');
var terrain = new dted.Terrain(fetcher);

terrain.fetchTileAt(lat, lon, function(err, tile) {
	console.log('Altitude: ', tile.getAltitudeAt(lat, lon));
});

terrain.getAltitudeAt(lat, lon, function(err, alt) {
	console.log('Altitude: ', alt);
});

Usage of Tile

var dted = require('lethexa-dted');

var buffer = ...dted-data...
var tile = dted.Tile( buffer );

// Iterate all altitude-values and their position
tile.forEachPosition( function(lat, lon, alt) {
	console.log('Position: ', lat, lon, alt);
});

// Find the next altitude-value
var alt = tile.getAltitudeAt(lat, lon);