我在 map 上有两个点,我知道它们之间的距离。现在,我需要在距离起点 X 米的地方找到一个新点。但是,我不知道如何找到新坐标。
var nextTrazadoPoint = new Coord {Lat = ...., Lng=...., Alt=...};
var previousTrazadoPoint = new Coord {Lat = ...., Lng=...., Alt...};
var fromCoords = new GeoCoordinate(nextTrazadoPoint.Lat, nextTrazadoPoint.Lng, nextTrazadoPoint.Alt);
var toCoords = new GeoCoordinate(previousTrazadoPoint .Lat, previousTrazadoPoint .Lng, previousTrazadoPoint .Alt);
var distance = fromCoords.GetDistanceTo(toCoords); //Let's say 1000 ¿meters?
现在我想从 previousTrazadoPoint
步行 200 米到 nextTrazadoPoint
//Vector from previousTrazadoPoint to nextTrazadoPoint
var vectorDireccion = new Vector(
(double)(nextTrazadoPoint.Latitud - previousTrazadoPoint.Latitud),
(double)(nextTrazadoPoint.Longitud - previousTrazadoPoint.Longitud)
);
//Normalize
vectorDireccion.Normalize();
//meters from previousTrazadoPoint
var distanciaARecorrer = 200;
//New coords
var vectorDestino = distanciaARecorrer * vectorDireccion;
point.Latitud = (decimal)vectorDestino.X + previousTrazadoPoint.Latitud;
point.Longitud = (decimal)vectorDestino.Y + previousTrazadoPoint.Longitud;
但是,当我在 Gmaps 上绘制新点时,它并没有放在两者之间。 有什么想法吗?
最佳答案
感谢@HansKilian 和@cletus ( Calculate distance between 2 GPS coordinates ),我找到了解决方案
private const double EARTH_RADIUS = 6378.1;
private static double ConvertToRadians(double angle)
{
return (Math.PI / 180) * angle;
}
private static double ConvertToDegree(double angle)
{
return angle * (180.0 / Math.PI);
}
private static double CalculateBearing(CoordsDto from, CoordsDto to)
{
var from_lat_rad = ConvertToRadians(from.Latitud);
var to_lat_rad = ConvertToRadians(to.Latitud);
var dif_lng_rad = ConvertToRadians(to.Longitud - from.Longitud);
double x = Math.Cos(from_lat_rad) * Math.Sin(to_lat_rad) - Math.Sin(from_lat_rad) * Math.Cos(to_lat_rad) * Math.Cos(dif_lng_rad);
double y = Math.Sin(dif_lng_rad) * Math.Cos(to_lat_rad);
// Math.Atan2 can return negative value, 0 <= output value < 2*PI expected
return (Math.Atan2(y, x) + Math.PI * 2) % (Math.PI * 2);
}
public static CoordsDto GetPointFarAway(CoordsDto from, CoordsDto to, double meterAwayFromStart)
{
var resp = new CoordsDto();
var bearing_rad = CalculateBearing(from, to);
var d = meterAwayFromStart * 0.001; //KM
var input_lat1_rad = ConvertToRadians(from.Latitud);
var input_lon1_rad = ConvertToRadians(from.Longitud);
var newPoint_lat_rad = Math.Asin(
Math.Sin(input_lat1_rad) * Math.Cos(d / EARTH_RADIUS) + Math.Cos(input_lat1_rad) * Math.Sin(d / EARTH_RADIUS) * Math.Cos(bearing_rad)
);
var newPoint_lon_rad = input_lon1_rad + Math.Atan2(
Math.Sin(bearing_rad) * Math.Sin(d / EARTH_RADIUS) * Math.Cos(input_lat1_rad),
Math.Cos(d / EARTH_RADIUS) - Math.Sin(input_lat1_rad) * Math.Sin(newPoint_lat_rad)
);
resp.Latitud = ConvertToDegree(newPoint_lat_rad);
resp.Longitud = ConvertToDegree(newPoint_lon_rad);
return resp;
}
关于c# - 从起点、终点和距离计算坐标,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/57088584/