// calculate distance in km using Haversine formula
// see http://www.movable-type.co.uk/scripts/latlong.html
public static double GetDistanceKm(Models.Location from, Models.Location to)
{
double delrad = Math.Acos(Math.Sin(ToRadians(from.Latitude)) * Math.Sin(ToRadians(to.Latitude)) +
Math.Cos(ToRadians(from.Latitude)) *
Math.Cos(ToRadians(to.Latitude)) *
Math.Cos(ToRadians(to.Longitude - from.Longitude)));
return(EarthRadiusKm * delrad);
}
// calculate bearing in degrees
// see http://www.movable-type.co.uk/scripts/latlong.html
public static double GetBearing(Models.Location from, Models.Location to)
{
var lat1 = ToRadians(from.Latitude);
var lat2 = ToRadians(to.Latitude);
var dLon = ToRadians(to.Longitude - from.Longitude);
var y = Math.Sin(dLon) * Math.Cos(lat2);
var x = Math.Cos(lat1) * Math.Sin(lat2) -
Math.Sin(lat1) * Math.Cos(lat2) * Math.Cos(dLon);
var brng = Math.Atan2(y, x);
return(ToDegrees(brng));
}
public const double KmToMiles = 0.621371; // to multiply instead of divide
// calculate distance in miles using Haversine formula
// see http://www.movable-type.co.uk/scripts/latlong.html
public static double GetDistanceMiles(Models.Location from, Models.Location to)
{
return(GetDistanceKm(from, to) * KmToMiles);
}
