/// <summary>
/// Creates instance of 3D shifted transformation.
/// </summary>
/// <param name="Tx"></param>
/// <param name="Ty"></param>
/// <param name="Tz"></param>
public Helmert(double Tx, double Ty, double Tz)
{
_matrix = new[, ] {
{ 0, 1, 0, Tx }, { 0, 1, 0, Ty }, { 0, 0, 1, Tz }, { 0, 0, 0, 1 }
};
_para = new TransParameters(null, null, Tx, Ty, Tz, 0, 0, 0, 0);
}
/// <summary>
///
/// </summary>
/// <param name="Tx"></param>
/// <param name="Ty"></param>
/// <param name="Tz"></param>
/// <param name="S"></param>
public BursaWolf(double Tx, double Ty, double Tz, double S = 0)
: base(Tx, Ty, Tz)
{
for (int i = 0; i < 3; i++)
{
_matrix[i, i] *= 1 + S * 1E-6;
}
_para = new TransParameters(null, null, Tx, Ty, Tz, S, 0, 0, 0);
}
/// <summary>
/// Molodensky-Badekas transformations
/// </summary>
/// <param name="point">space rectangular point</param>
/// <param name="para">(7+3) parameters</param>
/// <returns>space point in new datum</returns>
public static SpaceRectangularCoord Transform(SpaceRectangularCoord point, TransParameters para)
{
// the last three is special
double dX = point.X - para.GetValue("Px");
double dY = point.Y - para.GetValue("Py");
double dZ = point.Z - para.GetValue("Pz");
double X, Y, Z;
// formula is from https://en.wikipedia.org/wiki/Geographic_coordinate_conversion
X = point.X + para.Tx + (dX - para.Rz * dY + para.Ry * dZ) + para.S * 1E-6 * dX;
Y = point.Y + para.Ty + (para.Rz * dX + dY - para.Rx * dZ) + para.S * 1E-6 * dY;
Z = point.Z + para.Tz + (-para.Ry * dX + para.Rx * dY + dZ) + para.S * 1E-6 * dZ;
return(new SpaceRectangularCoord(X, Y, Z));
}
/// <summary>
/// Creates instance of 3D rotational and shifted transformation.
/// </summary>
/// <param name="para"></param>
public Helmert(TransParameters para)
{
_matrix = new[, ] {
{ 1, -para.Rz, para.Ry, para.Tx }, { para.Rz, 1, -para.Rx, para.Ty },
{ -para.Ry, para.Rx, 1, para.Tz }, { 0, 0, 0, 1 }
};
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
_matrix[i, j] *= (1 + para.S * 1E-6);
}
}
_para = para;
}
/// <summary>
/// transform the geodetic datum
/// </summary>
/// <param name="point">geodetic point</param>
/// <param name="from">source ellipsoid</param>
/// <param name="to">target ellipsoid</param>
/// <param name="para">three translation parameters</param>
/// <returns>geodetic point in new datum</returns>
public static GeodeticCoord Transform(GeodeticCoord point, Ellipsoid from, Ellipsoid to, TransParameters para)
{
double B = point.Latitude.Radians;
double L = point.Longitude.Radians;
double H = point.Height;
double sinB = Math.Sin(B);
double cosB = Math.Cos(B);
double sinL = Math.Sin(L);
double cosL = Math.Cos(L);
double a = from.SemiMajorAxis;
double b_a = 1 - from.Flattening;
double da = to.SemiMajorAxis - from.SemiMajorAxis;
double df = to.Flattening - from.Flattening;
double ee = from.ee;
double w = 1.0 - ee * sinB * sinB;
double Rm = a * (1.0 - ee) / Math.Pow(w, 1.5);
double Rn = a / Math.Sqrt(w);
// formula is from http://earth-info.nga.mil/GandG/coordsys/datums/standardmolodensky.html
double dB = (-para.Tx * sinB * cosL - para.Ty * sinB * sinL + para.Tz * cosB
+ da * (Rn * ee * sinB * cosB) / a
+ df * (Rm / b_a + Rn * b_a) * sinB * cosB) / (Rm + H);
double dL = (-para.Tx * sinL + para.Ty * cosL) / ((Rn + H) * cosB);
double dH = para.Tx * cosB * cosL + para.Ty * cosB * sinL + para.Tz * sinB
- da * a / Rn + df * Rn * b_a * sinB * sinB;
return(new GeodeticCoord(Latitude.FromRadians(B + dB), Longitude.FromRadians(L + dL), H + dH));
}
/// <summary>
/// Creates instance of 2D rotational and shifted transformation.
/// </summary>
/// <param name="theta"></param>
/// <param name="Tx"></param>
/// <param name="Ty"></param>
public Helmert(Angle theta, double Tx = 0, double Ty = 0)
: base(theta, Tx, Ty)
{
_para = null;
}
/// <summary>
///
/// </summary>
/// <param name="para"></param>
public BursaWolf(TransParameters para)
: base(para)
{
_para = para;
}
