public static double DistanceBetween(GeoCoordinate from, GeoCoordinate to)
{
// we are working in radians and not degrees
var flatrad = MathHelper.DegreesToRadians(from.Latitude);
var flonrad = MathHelper.DegreesToRadians(from.Longitude);
// we are working in radians and not degrees
var tlatrad = MathHelper.DegreesToRadians(to.Latitude);
var tlonrad = MathHelper.DegreesToRadians(to.Longitude);
var latRadDelta = tlatrad - flatrad;
var lonRadDelta = tlonrad - flonrad;
var h =
// haversine function
Math.Pow(Math.Sin(latRadDelta * 0.5), 2)
+
Math.Cos(tlatrad)
*
Math.Cos(flatrad)
*
// haversine function
Math.Pow(Math.Sin(lonRadDelta * 0.5), 2)
;
// inverse haversine function
var distance =
Math.Asin(Math.Min(1, Math.Sqrt(h)))
*
// Earth radius in meters
6378137.0
*
2;
return distance;
}
public double DistanceBetween(GeoCoordinate coordinate, DistanceUnit unit)
{
return DistanceBetween(this, coordinate, unit);
}
public double DistanceBetween(GeoCoordinate coordinate)
{
return DistanceBetween(this, coordinate);
}
public static double DistanceBetween(GeoCoordinate from, GeoCoordinate to, DistanceUnit unit)
{
return MathHelper.ConvertDistance(DistanceBetween(from, to), DistanceUnit.Meters, unit);
}
