Updated great circle and rhumb line calculation

This commit is contained in:
ClemensF 2021-02-10 22:58:17 +01:00
parent f4f783776a
commit 87ff5043f6
2 changed files with 149 additions and 150 deletions

View file

@ -9,7 +9,7 @@ using System.Linq;
namespace MapControl
{
/// <summary>
/// A collection of Locations with support for parsing.
/// A collection of Locations with support for string parsing and calculation of great circle and rhumb line locations.
/// </summary>
#if !WINDOWS_UWP
[System.ComponentModel.TypeConverter(typeof(LocationCollectionConverter))]
@ -30,11 +30,155 @@ namespace MapControl
{
}
public void Add(double latitude, double longitude)
{
if (Count > 0)
{
var deltaLon = longitude - this[Count - 1].Longitude;
if (deltaLon < -180d)
{
longitude += 360d;
}
else if (deltaLon > 180)
{
longitude -= 360;
}
}
Add(new Location(latitude, longitude));
}
public static LocationCollection Parse(string s)
{
var strings = s.Split(new char[] { ' ', ';' }, StringSplitOptions.RemoveEmptyEntries);
return new LocationCollection(strings.Select(l => Location.Parse(l)));
}
/// <summary>
/// see https://en.wikipedia.org/wiki/Great-circle_navigation
/// </summary>
public static LocationCollection CalculateGreatCircleLocations(Location location1, Location location2, double resolution = 1d)
{
if (resolution <= 0d)
{
throw new ArgumentOutOfRangeException(
nameof(resolution), "The parameter resolution must be greater than zero.");
}
resolution *= Math.PI / 180d;
var lat1 = location1.Latitude * Math.PI / 180d;
var lon1 = location1.Longitude * Math.PI / 180d;
var lat2 = location2.Latitude * Math.PI / 180d;
var lon2 = location2.Longitude * Math.PI / 180d;
var cosLat1 = Math.Cos(lat1);
var sinLat1 = Math.Sin(lat1);
var cosLat2 = Math.Cos(lat2);
var sinLat2 = Math.Sin(lat2);
var cosLon12 = Math.Cos(lon2 - lon1);
var sinLon12 = Math.Sin(lon2 - lon1);
var a = cosLat1 * sinLat2 - sinLat1 * cosLat2 * cosLon12;
var b = cosLat2 * sinLon12;
var s12 = Math.Atan2(Math.Sqrt(a * a + b * b), sinLat1 * sinLat2 + cosLat1 * cosLat2 * cosLon12);
var locations = new LocationCollection(new Location(location1.Latitude, location1.Longitude));
if (s12 > resolution)
{
var n = (int)Math.Round(s12 / resolution);
var az1 = Math.Atan2(sinLon12, cosLat1 * sinLat2 / cosLat2 - sinLat1 * cosLon12);
var cosAz1 = Math.Cos(az1);
var sinAz1 = Math.Sin(az1);
var az0 = Math.Atan2(sinAz1 * cosLat1, Math.Sqrt(cosAz1 * cosAz1 + sinAz1 * sinAz1 * sinLat1 * sinLat1));
var sinAz0 = Math.Sin(az0);
var cosAz0 = Math.Cos(az0);
var s01 = Math.Atan2(sinLat1, cosLat1 * cosAz1);
var lon0 = lon1 - Math.Atan2(sinAz0 * Math.Sin(s01), Math.Cos(s01));
for (int i = 1; i < n; i++)
{
double s = s01 + i * s12 / n;
double sinS = Math.Sin(s);
double cosS = Math.Cos(s);
double lat = Math.Atan2(cosAz0 * sinS, Math.Sqrt(cosS * cosS + sinAz0 * sinAz0 * sinS * sinS));
double lon = Math.Atan2(sinAz0 * sinS, cosS) + lon0;
locations.Add(lat * 180d / Math.PI, lon * 180d / Math.PI);
}
}
locations.Add(location2.Latitude, location2.Longitude);
return locations;
}
/// <summary>
/// see https://en.wikipedia.org/wiki/Rhumb_line
/// </summary>
public static LocationCollection CalculateRhumbLineLocations(Location location1, Location location2, double resolution = 1d)
{
if (resolution <= 0d)
{
throw new ArgumentOutOfRangeException(
nameof(resolution), "The parameter resolution must be greater than zero.");
}
resolution *= Math.PI / 180d;
var lat1 = location1.Latitude;
var lat2 = location2.Latitude;
var y1 = WebMercatorProjection.LatitudeToY(lat1);
var y2 = WebMercatorProjection.LatitudeToY(lat2);
if (double.IsInfinity(y1))
{
throw new ArgumentOutOfRangeException(
nameof(location1), "The parameter location1 must have an absolute latitude value of less than 90 degrees.");
}
if (double.IsInfinity(y2))
{
throw new ArgumentOutOfRangeException(
nameof(location2), "The parameter location2 must have an absolute latitude value of less than 90 degrees.");
}
var lon1 = location1.Longitude;
var lon2 = location2.Longitude;
var dlat = lat2 - lat1;
var dlon = lon2 - lon1;
var dy = y2 - y1;
// sec(beta) = 1 / cos(atan(dx,dy)) = sqrt(1 + (dx/dy)^2)
var sec = Math.Sqrt(1d + dlon * dlon / (dy * dy));
var s12 = sec < 1000d
? Math.Abs(dlat * Math.PI / 180d * sec)
: Math.Abs(dlon * Math.PI / 180d);
var locations = new LocationCollection(new Location(lat1, lon1));
if (s12 > resolution)
{
var n = (int)Math.Round(s12 / resolution);
for (int i = 1; i < n; i++)
{
double lon = lon1 + i * dlon / n;
double lat = WebMercatorProjection.YToLatitude(y1 + i * dy / n);
locations.Add(lat, lon);
}
}
locations.Add(lat2, lon2);
return locations;
}
}
}

View file

@ -3,7 +3,6 @@
// Licensed under the Microsoft Public License (Ms-PL)
using System;
using System.Linq;
namespace MapControl
{
@ -15,7 +14,8 @@ namespace MapControl
/// <summary>
/// see https://en.wikipedia.org/wiki/Great-circle_navigation
/// </summary>
public static double GreatCircleDistance(this Location location1, Location location2, double earthRadius = MapProjection.Wgs84EquatorialRadius)
public static double GreatCircleDistance(
this Location location1, Location location2, double earthRadius = MapProjection.Wgs84EquatorialRadius)
{
var lat1 = location1.Latitude * Math.PI / 180d;
var lon1 = location1.Longitude * Math.PI / 180d;
@ -37,7 +37,8 @@ namespace MapControl
/// <summary>
/// see https://en.wikipedia.org/wiki/Great-circle_navigation
/// </summary>
public static Location GreatCircleLocation(this Location location, double azimuth, double distance, double earthRadius = MapProjection.Wgs84EquatorialRadius)
public static Location GreatCircleLocation(
this Location location, double azimuth, double distance, double earthRadius = MapProjection.Wgs84EquatorialRadius)
{
var s12 = distance / earthRadius;
var az1 = azimuth * Math.PI / 180d;
@ -54,151 +55,5 @@ namespace MapControl
return new Location(lat2 * 180d / Math.PI, lon2 * 180d / Math.PI);
}
public static LocationCollection CalculateMeridianLocations(this Location location, double latitude2, double resolution = 1d)
{
if (resolution <= 0d)
{
throw new ArgumentOutOfRangeException("The parameter resolution must be greater than zero.");
}
var locations = new LocationCollection();
var s = latitude2 - location.Latitude;
var n = (int)Math.Ceiling(Math.Abs(s) / resolution);
for (int i = 0; i <= n; i++)
{
locations.Add(new Location(location.Latitude + i * s / n, location.Longitude));
}
return locations;
}
/// <summary>
/// see https://en.wikipedia.org/wiki/Great-circle_navigation
/// </summary>
public static LocationCollection CalculateGreatCircleLocations(this Location location1, Location location2, double resolution = 1d)
{
if (resolution <= 0d)
{
throw new ArgumentOutOfRangeException("The parameter resolution must be greater than zero.");
}
if (location1.Longitude == location2.Longitude ||
location1.Latitude <= -90d || location1.Latitude >= 90d ||
location2.Latitude <= -90d || location2.Latitude >= 90d)
{
return CalculateMeridianLocations(location1, location2.Latitude);
}
var locations = new LocationCollection(new Location(location1.Latitude, location1.Longitude));
var lat1 = location1.Latitude * Math.PI / 180d;
var lon1 = location1.Longitude * Math.PI / 180d;
var lat2 = location2.Latitude * Math.PI / 180d;
var lon2 = location2.Longitude * Math.PI / 180d;
var cosLat1 = Math.Cos(lat1);
var sinLat1 = Math.Sin(lat1);
var cosLat2 = Math.Cos(lat2);
var sinLat2 = Math.Sin(lat2);
var cosLon12 = Math.Cos(lon2 - lon1);
var sinLon12 = Math.Sin(lon2 - lon1);
var cosS12 = sinLat1 * sinLat2 + cosLat1 * cosLat2 * cosLon12;
var s12 = Math.Acos(Math.Min(Math.Max(cosS12, -1d), 1d));
var n = (int)Math.Ceiling(s12 / resolution * 180d / Math.PI);
if (n > 1)
{
var az1 = Math.Atan2(sinLon12, cosLat1 * sinLat2 / cosLat2 - sinLat1 * cosLon12);
var cosAz1 = Math.Cos(az1);
var sinAz1 = Math.Sin(az1);
var az0 = Math.Atan2(sinAz1 * cosLat1, Math.Sqrt(cosAz1 * cosAz1 + sinAz1 * sinAz1 * sinLat1 * sinLat1));
var sinAz0 = Math.Sin(az0);
var cosAz0 = Math.Cos(az0);
var s01 = Math.Atan2(sinLat1, cosLat1 * cosAz1);
var lon0 = lon1 - Math.Atan2(sinAz0 * Math.Sin(s01), Math.Cos(s01));
for (int i = 1; i < n; i++)
{
double s = s01 + i * s12 / n;
double sinS = Math.Sin(s);
double cosS = Math.Cos(s);
double lat = Math.Atan2(cosAz0 * sinS, Math.Sqrt(cosS * cosS + sinAz0 * sinAz0 * sinS * sinS));
double lon = Math.Atan2(sinAz0 * sinS, cosS) + lon0;
locations.Add(lat * 180d / Math.PI, lon * 180d / Math.PI);
}
}
locations.Add(location2.Latitude, location2.Longitude);
return locations;
}
/// <summary>
/// see https://en.wikipedia.org/wiki/Rhumb_line
/// </summary>
public static LocationCollection CalculateRhumbLineLocations(this Location location1, Location location2, double resolution = 1d)
{
if (resolution <= 0d)
{
throw new ArgumentOutOfRangeException("The parameter resolution must be greater than zero.");
}
var y1 = WebMercatorProjection.LatitudeToY(location1.Latitude);
if (double.IsInfinity(y1))
{
throw new ArgumentOutOfRangeException("The parameter location1 must have an absolute latitude value of less than 90 degrees.");
}
var y2 = WebMercatorProjection.LatitudeToY(location2.Latitude);
if (double.IsInfinity(y2))
{
throw new ArgumentOutOfRangeException("The parameter location2 must have an absolute latitude value of less than 90 degrees.");
}
var x1 = location1.Longitude;
var x2 = location2.Longitude;
var dx = x2 - x1;
var dy = y2 - y1;
var s = Math.Sqrt(dx * dx + dy * dy);
var n = (int)Math.Ceiling(s / resolution);
var locations = new LocationCollection(new Location(location1.Latitude, location1.Longitude));
for (int i = 1; i < n; i++)
{
double x = x1 + i * dx / n;
double y = y1 + i * dy / n;
locations.Add(WebMercatorProjection.YToLatitude(y), x);
}
locations.Add(location2.Latitude, location2.Longitude);
return locations;
}
public static void Add(this LocationCollection locations, double latitude, double longitude)
{
if (locations.Count > 0)
{
var deltaLon = longitude - locations.Last().Longitude;
if (deltaLon < -180d)
{
longitude += 360d;
}
else if (deltaLon > 180)
{
longitude -= 360;
}
}
locations.Add(new Location(latitude, longitude));
}
}
}