public double CalculateSpeed()
{
TimeSpan elapsedTime = DateTime.UtcNow - initialDate;
GeoLocation GL = new GeoLocation();
GL.Location();
/*dlon = lon2 - lon1
* dlat = lat2 - lat1
* a = (sin(dlat/2))^2 + cos(lat1) * cos(lat2) * (sin(dlon/2))^2
* c = 2 * atan2( sqrt(a), sqrt(1-a) )
* d = R * c (where R is the radius of the Earth)*/
lat1 = DegreeToRadian(ps.getInitialLatitude());
lat2 = DegreeToRadian(GL.getLatitude());
lon1 = DegreeToRadian(ps.getInitialLongitude());
lon2 = DegreeToRadian(GL.getLongitude());
double speed;
/*
* MessageBox.Show("1 " + lat1 + " 2 " + lon1);
* MessageBox.Show("1 " + lat2 + " 2 " + lon2);
* MessageBox.Show(elapsedTime.TotalHours.ToString());
*/
if (Math.Round(lat1, 3) == Math.Round(lat2, 3) && Math.Round(lon1, 3) == Math.Round(lon2, 3))
{
speed = 0;
}
else
{
double dlon = lon2 - lon1;
double dlat = lat2 - lat1;
double a = Math.Pow((Math.Sin(dlat / 2)), 2) + Math.Cos(lat1) * Math.Cos(lat2) * Math.Pow((Math.Sin(dlon / 2)), 2);
double c = 2 * Math.Atan2(Math.Sqrt(a), Math.Sqrt(1 - a));
double distance = 3961 * c; //3961 miles = Radius of the Earth. It is equivalent to 6373 km
// miles / second
speed = distance / elapsedTime.TotalHours;
// return Math.Round(speed,2);
// MessageBox.Show(elapsedTime.TotalHours.ToString());
}
return(speed);
}