ClemensFischer/XAML-Map-Control
1
0
Fork 0
mirror of https://github.com/ClemensFischer/XAML-Map-Control.git synced 2026-04-08 16:05:50 +00:00
Code Issues Projects Releases Packages Wiki Activity

Updated MapProjection and MapGraticule

Browse source
This commit is contained in:
ClemensFischer 2026-02-01 01:42:24 +01:00
parent 2a45c1165c
commit cfed3575ac
16 changed files with 392 additions and 355 deletions
Download patch file Download diff file Expand all files Collapse all files

110
MapControl/Shared/TransverseMercatorProjection.cs
View file

@ -9,9 +9,10 @@ using Avalonia;
namespace MapControl
{
/// <summary>
/// Transverse Mercator Projection.
/// See https://en.wikipedia.org/wiki/Transverse_Mercator_projection
/// and https://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system.
/// Transverse Mercator Projection. See
/// https://en.wikipedia.org/wiki/Transverse_Mercator_projection,
/// https://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system,
/// https://en.wikipedia.org/wiki/Transverse_Mercator_projection#Convergence.
/// </summary>
public class TransverseMercatorProjection : MapProjection
{
@ -27,6 +28,11 @@ namespace MapControl
private double f1; // A/a
private double f2; // 2*sqrt(n)/(1+n)
public TransverseMercatorProjection()
{
Flattening = Wgs84Flattening;
}
public double Flattening
{
get;
@ -50,43 +56,20 @@ namespace MapControl
}
}
public double CentralMeridian { get; set; }
public double ScaleFactor { get; set; } = 0.9996;
public double FalseEasting { get; set; } = 5e5;
public double FalseNorthing { get; set; }
public TransverseMercatorProjection()
{
Flattening = Wgs84Flattening;
}
public override Point LocationToMap(double latitude, double longitude)
public override double GridConvergence(double latitude, double longitude)
{
// φ
var phi = latitude * Math.PI / 180d;
var sinPhi = Math.Sin(phi);
// t
var t = Math.Sinh(Atanh(sinPhi) - f2 * Atanh(f2 * sinPhi));
// λ - λ0
var dLambda = (longitude - CentralMeridian) * Math.PI / 180d;
// ξ'
var xi_ = Math.Atan2(t, Math.Cos(dLambda));
// η'
var eta_ = Atanh(Math.Sin(dLambda) / Math.Sqrt(1d + t * t));
// k0 * A
var k0A = ScaleFactor * EquatorialRadius * f1;
var x = FalseEasting + k0A * (eta_ +
a1 * Math.Cos(2d * xi_) * Math.Sinh(2d * eta_) +
a2 * Math.Cos(4d * xi_) * Math.Sinh(4d * eta_) +
a3 * Math.Cos(6d * xi_) * Math.Sinh(6d * eta_));
var y = FalseNorthing + k0A * (xi_ +
a1 * Math.Sin(2d * xi_) * Math.Cosh(2d * eta_) +
a2 * Math.Sin(4d * xi_) * Math.Cosh(4d * eta_) +
a3 * Math.Sin(6d * xi_) * Math.Cosh(6d * eta_));
return new Point(x, y);
// γ calculation for the sphere is sufficiently accurate
//
return Math.Atan(Math.Tan(dLambda) * Math.Sin(phi)) * 180d / Math.PI;
}
public override Matrix RelativeTransform(double latitude, double longitude)
@ -120,7 +103,7 @@ namespace MapControl
var m = (1d - n) / (1d + n) * Math.Tan(phi);
var k = ScaleFactor * f1 * Math.Sqrt((1d + m * m) * (sigma * sigma + tau * tau) / (t * t + cosLambda * cosLambda));
// γ, meridian convergence angle
// γ, grid convergence
var gamma = Math.Atan2(tau * u + sigma * t * tanLambda, sigma * u - tau * t * tanLambda);
var transform = new Matrix(k, 0d, 0d, k, 0d, 0d);
@ -129,6 +112,35 @@ namespace MapControl
return transform;
}
public override Point LocationToMap(double latitude, double longitude)
{
// φ
var phi = latitude * Math.PI / 180d;
var sinPhi = Math.Sin(phi);
// t
var t = Math.Sinh(Atanh(sinPhi) - f2 * Atanh(f2 * sinPhi));
// λ - λ0
var dLambda = (longitude - CentralMeridian) * Math.PI / 180d;
// ξ'
var xi_ = Math.Atan2(t, Math.Cos(dLambda));
// η'
var eta_ = Atanh(Math.Sin(dLambda) / Math.Sqrt(1d + t * t));
// k0 * A
var k0A = ScaleFactor * EquatorialRadius * f1;
var x = FalseEasting + k0A * (eta_ +
a1 * Math.Cos(2d * xi_) * Math.Sinh(2d * eta_) +
a2 * Math.Cos(4d * xi_) * Math.Sinh(4d * eta_) +
a3 * Math.Cos(6d * xi_) * Math.Sinh(6d * eta_));
var y = FalseNorthing + k0A * (xi_ +
a1 * Math.Sin(2d * xi_) * Math.Cosh(2d * eta_) +
a2 * Math.Sin(4d * xi_) * Math.Cosh(4d * eta_) +
a3 * Math.Sin(6d * xi_) * Math.Cosh(6d * eta_));
return new Point(x, y);
}
public override Location MapToLocation(double x, double y)
{
// k0 * A
@ -162,42 +174,6 @@ namespace MapControl
dLambda * 180d / Math.PI + CentralMeridian);
}
public override double GridConvergence(double x, double y)
{
// k0 * A
var k0A = ScaleFactor * EquatorialRadius * f1;
// ξ
var xi = (y - FalseNorthing) / k0A;
// η
var eta = (x - FalseEasting) / k0A;
// ξ'
var xi_ = xi -
b1 * Math.Sin(2d * xi) * Math.Cosh(2d * eta) -
b2 * Math.Sin(4d * xi) * Math.Cosh(4d * eta) -
b3 * Math.Sin(6d * xi) * Math.Cosh(6d * eta);
// η'
var eta_ = eta -
b1 * Math.Cos(2d * xi) * Math.Sinh(2d * eta) -
b2 * Math.Cos(4d * xi) * Math.Sinh(4d * eta) -
b3 * Math.Cos(6d * xi) * Math.Sinh(6d * eta);
// σ'
var sigma_ = 1 -
2d * b1 * Math.Cos(2d * xi) * Math.Cosh(2d * eta) +
4d * b2 * Math.Cos(4d * xi) * Math.Cosh(4d * eta) +
6d * b3 * Math.Cos(6d * xi) * Math.Cosh(6d * eta);
// τ'
var tau_ =
2d * b1 * Math.Sin(2d * xi) * Math.Sinh(2d * eta) +
4d * b2 * Math.Sin(4d * xi) * Math.Sinh(4d * eta) +
6d * b3 * Math.Sin(6d * xi) * Math.Sinh(6d * eta);
var tanXi_tanhEta_ = Math.Tan(xi_) * Math.Tanh(eta_);
// γ
var gamma = Math.Atan2(tau_ + sigma_ * tanXi_tanhEta_, sigma_ + -tau_ * tanXi_tanhEta_);
return gamma * 180d / Math.PI;
}
#if NETFRAMEWORK
private static double Atanh(double x) => Math.Log((1d + x) / (1d - x)) / 2d;
#else