/// <summary>
/// Returns three dimensional cartesian coordinates for this EarthCoordinate
/// with vertical orientation to the center of the earth
/// and horizontal orientation to the polar coordinates
/// <remarks>
/// X is meters -East/+West from the start
/// Y is meters -South/+North from the start
/// Z is meters -Below/+Above the start
/// </remarks>
/// </summary>
/// <param name="start"></param>
/// <returns></returns>
public Point3 OffsetFromStart(EarthCoordinates start)
{
// Distance between start and end Longitude in meters.
double y = 2.0 * Math.PI * ((((start._polarAxisMeters + this._polarAxisMeters) / 2.0)) / 360.0) * (start.Longitude - this.Longitude);
// Difference in altitude
double z = (this.AltitudeMeters - start.AltitudeMeters);
// To calculate the difference in Latitude,
// find the Longitude and Altitude midpoints
double midLongitude = (start.Longitude + this.Longitude) / 2.0;
double midAltitude = (start.AltitudeMeters + this.AltitudeMeters) / 2.0;
EarthCoordinates lat1;
if ((Math.Abs(midAltitude) > 20.0) || (Math.Abs(midLongitude) > 0.0001))
{
// The points are spread apart,
// so plot two new points at the starting and ending Latitude
// and using the midpoints of Longitude and Altitude.
lat1 = new EarthCoordinates(start.Latitude, midLongitude, midAltitude, start.DateTime, start.HorizontalDilutionOfPrecision, start.VerticalDilutionOfPrecision);
}
else
{
// The points are near the same Longitude and Altitude,
// so calculate Latitude using the start Longitude and Altitude.
lat1 = start;
midLongitude = start.Longitude;
midAltitude = start.AltitudeMeters;
}
EarthCoordinates lat2 = new EarthCoordinates(this.Latitude, midLongitude, midAltitude, this.DateTime, this.HorizontalDilutionOfPrecision, this.VerticalDilutionOfPrecision);
// Finally, measure the distance between these points.
double x = lat2.DistanceFromStart(lat1);
return(new Point3(x, y, z));
}
/// <summary>
/// Returns three dimensional cartesian coordinates for this EarthCoordinate
/// with vertical orientation to the center of the earth
/// and horizontal orientation to the polar coordinates
/// <remarks>
/// X is meters -East/+West from the start
/// Y is meters -South/+North from the start
/// Z is meters -Below/+Above the start
/// </remarks>
/// </summary>
/// <param name="start"></param>
/// <returns></returns>
public Point3 OffsetFromStart(EarthCoordinates start)
{
// Distance between start and end Longitude in meters.
double y = 2.0 * Math.PI * ((((start._polarAxisMeters + this._polarAxisMeters) / 2.0)) / 360.0) * (start.Longitude - this.Longitude);
// Difference in altitude
double z = (this.AltitudeMeters - start.AltitudeMeters);
// To calculate the difference in Latitude,
// find the Longitude and Altitude midpoints
double midLongitude = (start.Longitude + this.Longitude) / 2.0;
double midAltitude = (start.AltitudeMeters + this.AltitudeMeters) / 2.0;
EarthCoordinates lat1;
if ((Math.Abs(midAltitude) > 20.0) || (Math.Abs(midLongitude) > 0.0001))
{
// The points are spread apart,
// so plot two new points at the starting and ending Latitude
// and using the midpoints of Longitude and Altitude.
lat1 = new EarthCoordinates(start.Latitude, midLongitude, midAltitude, start.DateTime, start.HorizontalDilutionOfPrecision, start.VerticalDilutionOfPrecision);
}
else
{
// The points are near the same Longitude and Altitude,
// so calculate Latitude using the start Longitude and Altitude.
lat1 = start;
midLongitude = start.Longitude;
midAltitude = start.AltitudeMeters;
}
EarthCoordinates lat2 = new EarthCoordinates(this.Latitude, midLongitude, midAltitude, this.DateTime, this.HorizontalDilutionOfPrecision, this.VerticalDilutionOfPrecision);
// Finally, measure the distance between these points.
double x = lat2.DistanceFromStart(lat1);
return new Point3(x, y, z);
}
