Looking for resources or algorithm to calculate the following in a navigation app:
If my current GPS position is (0,0) and I'm heading 32 degrees at 15 miles per hour, how can I calculate what my position will be in 10 seconds?
i.e.: GPSCoordinate predictedCoord = GPSCoordinate.FromLatLong(0, 0).AddByMovement(32, 15, TimeSpan.FromSeconds(10));
Edit: Current code based on answer below:
public GPSCoordinate AddMovementMilesPerHour(double heading, double speedMph, TimeSpan duration)
{
double x = speedMph * System.Math.Sin(heading * pi / 180) * duration.TotalSeconds / 3600;
double y = speedMph * System.Math.Cos(heading * pi / 180) * duration.TotalSeconds / 3600;
double newLat = this.Latitude + 180 / pi * y / earthRadius;
double newLong = this.Longitude + 180 / pi / System.Math.Sin(this.Latitude * pi / 180) * x / earthRadius;
return GPSCoordinate.FromLatLong(newLat, newLong);
}
Here is the complete parametric answer :
variables :
heading
: heading (i.e. backwards angle from azimuth 0°, in degrees)speed
: velocity (i.e. norm of the speed vector, in miles/hour)lat0
, lon0
: initial coordinates in degreesdtime
: time interval from the start position, in secondslat
, lon
: predicted coordinates in degreespi
: the pi constant (3.14159...)Rt
: Earth radius in miles (6378137.0 meters which makes 3964.037911746 miles) In an (East, North) local frame, the position after the time interval is :
x = speed * sin(heading*pi/180) * dtime / 3600;
y = speed * cos(heading*pi/180) * dtime / 3600;
(with coordinates in miles)
From there you can compute the new position in the WGS84 frame (i.e. latitude and longitude) :
lat = lat0 + 180 / pi * y / Rt;
lon = lon0 + 180 / pi / sin(lat0*pi/180) * x / Rt;
Edit : corrected the last line : *sin(phi) to /sin(phi)
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