/// <summary>
/// Reads the proj4 parameters and parses out the ones that control the
/// datum.
/// </summary>
/// <param name="parameters"></param>
/// <remarks>Originally ported from pj_datum_set.c</remarks>
public void ReadProj4Params(Dictionary <string, string> parameters)
{
DatumType = DatumTypes.Unknown;
/* -------------------------------------------------------------------- */
/* Is there a datum definition in the parameters list? If so, */
/* add the defining values to the parameter list. Notice that */
/* this will append the ellipse definition as well as the */
/* towgs84= and related parameters. It should also be pointed */
/* out that the addition is permanent rather than temporary */
/* like most other keyword expansion so that the ellipse */
/* definition will last into the pj_ell_set() function called */
/* after this one. */
/* -------------------------------------------------------------------- */
if (parameters.ContainsKey("datum"))
{
AssignStandardDatum(parameters["datum"]);
// Even though th ellipsoid is set by its known definition, we permit overriding it with a specifically defined ellps parameter
}
// ELLIPSOID PARAMETER
if (parameters.ContainsKey("ellps"))
{
Spheroid = new Spheroid(parameters["ellps"]);
}
else
{
if (parameters.ContainsKey("a"))
{
Spheroid.EquatorialRadius = double.Parse(parameters["a"]);
}
if (parameters.ContainsKey("b"))
{
Spheroid.PolarRadius = double.Parse(parameters["b"]);
}
if (parameters.ContainsKey("rf"))
{
Spheroid.SetInverseFlattening(double.Parse(parameters["rf"]));
}
if (parameters.ContainsKey("R"))
{
Spheroid.EquatorialRadius = double.Parse(parameters["R"]);
}
}
// DATUM PARAMETER
if (parameters.ContainsKey("nadgrids"))
{
_nadGrids = parameters["nadgrids"].Split(',');
_datumtype = DatumTypes.GridShift;
}
else if (parameters.ContainsKey("towgs84"))
{
string[] rawVals = parameters["towgs84"].Split(',');
_toWGS84 = new double[rawVals.Length];
for (int i = 0; i < rawVals.Length; i++)
{
_toWGS84[i] = double.Parse(rawVals[i]);
}
_datumtype = DatumTypes.Param7;
if (_toWGS84.Length < 7)
{
_datumtype = DatumTypes.Param3;
}
if (_toWGS84[3] == 0.0 && _toWGS84[4] == 0.0 &&
_toWGS84[5] == 0.0 && _toWGS84[6] == 0.0)
{
_datumtype = DatumTypes.Param3;
}
if (_datumtype == DatumTypes.Param7)
{
// Trnasform from arc seconds to radians
_toWGS84[3] *= SecToRad;
_toWGS84[4] *= SecToRad;
_toWGS84[5] *= SecToRad;
// transform from parts per millon to scaling factor
_toWGS84[6] = (_toWGS84[6] / 1000000.0) + 1;
}
}
}
/// <summary>
/// Reads the proj4 parameters and parses out the ones that control the
/// datum.
/// </summary>
/// <param name="parameters"></param>
/// <remarks>Originally ported from pj_datum_set.c</remarks>
public void ReadProj4Params(Dictionary<string, string> parameters)
{
DatumType = DatumTypes.Unknown;
/* -------------------------------------------------------------------- */
/* Is there a datum definition in the parameters list? If so, */
/* add the defining values to the parameter list. Notice that */
/* this will append the ellipse definition as well as the */
/* towgs84= and related parameters. It should also be pointed */
/* out that the addition is permanent rather than temporary */
/* like most other keyword expansion so that the ellipse */
/* definition will last into the pj_ell_set() function called */
/* after this one. */
/* -------------------------------------------------------------------- */
if (parameters.ContainsKey("datum"))
{
AssignStandardDatum(parameters["datum"]);
// Even though th ellipsoid is set by its known definition, we permit overriding it with a specifically defined ellps parameter
}
// ELLIPSOID PARAMETER
if (parameters.ContainsKey("ellps"))
{
Spheroid = new Spheroid(parameters["ellps"]);
}
else
{
if (parameters.ContainsKey("a"))
{
Spheroid.EquatorialRadius = double.Parse(parameters["a"]);
}
if (parameters.ContainsKey("b"))
{
Spheroid.PolarRadius = double.Parse(parameters["b"]);
}
if (parameters.ContainsKey("rf"))
{
Spheroid.SetInverseFlattening(double.Parse(parameters["rf"]));
}
if (parameters.ContainsKey("R"))
{
Spheroid.EquatorialRadius = double.Parse(parameters["R"]);
}
}
// DATUM PARAMETER
if (parameters.ContainsKey("nadgrids"))
{
_nadGrids = parameters["nadgrids"].Split(',');
_datumtype = DatumTypes.GridShift;
}
else if (parameters.ContainsKey("towgs84"))
{
string[] rawVals = parameters["towgs84"].Split(',');
_toWGS84 = new double[rawVals.Length];
for(int i = 0; i < rawVals.Length; i++)
{
_toWGS84[i] = double.Parse(rawVals[i]);
}
_datumtype = DatumTypes.Param7;
if (_toWGS84.Length < 7) _datumtype = DatumTypes.Param3;
if (_toWGS84[3] == 0.0 && _toWGS84[4] == 0.0 &&
_toWGS84[5] == 0.0 && _toWGS84[6] == 0.0) _datumtype = DatumTypes.Param3;
if(_datumtype == DatumTypes.Param7)
{
// Trnasform from arc seconds to radians
_toWGS84[3] *= SecToRad;
_toWGS84[4] *= SecToRad;
_toWGS84[5] *= SecToRad;
// transform from parts per millon to scaling factor
_toWGS84[6] = (_toWGS84[6]/1000000.0) + 1;
}
}
}
private void AssignStandardDatum(string datumName)
{
string id = datumName.ToLower();
switch (id)
{
case "wgs84":
_toWGS84 = new double[] { 0, 0, 0 };
_spheroid = new Spheroid(Proj4Ellipsoids.WGS_1984);
_description = "WGS 1984";
_datumtype = DatumTypes.WGS84;
_name = "D_WGS_1984";
break;
case "ggrs87":
_toWGS84 = new[] { -199.87, 74.79, 246.62 };
_spheroid = new Spheroid(Proj4Ellipsoids.GRS_1980);
_description = "Greek Geodetic Reference System 1987";
_datumtype = DatumTypes.Param3;
break;
case "nad83":
_toWGS84 = new double[] { 0, 0, 0 };
_spheroid = new Spheroid(Proj4Ellipsoids.GRS_1980);
_description = "North American Datum 1983";
_datumtype = DatumTypes.WGS84;
break;
case "nad27":
_nadGrids = new[] { "@conus", "@alaska", "@ntv2_0.gsb", "@ntv1_can.dat" };
_spheroid = new Spheroid(Proj4Ellipsoids.Clarke_1866);
_description = "North American Datum 1927";
_datumtype = DatumTypes.GridShift;
break;
case "potsdam":
_toWGS84 = new[] { 606.0, 23.0, 413.0 };
_spheroid = new Spheroid(Proj4Ellipsoids.Bessel_1841);
_description = "Potsdam Rauenberg 1950 DHDN";
_datumtype = DatumTypes.Param3;
break;
case "carthage":
_toWGS84 = new[] { -263.0, 6, 413 };
_spheroid = new Spheroid(Proj4Ellipsoids.ClarkeModified_1880);
_description = "Carthage 1934 Tunisia";
_datumtype = DatumTypes.Param3;
break;
case "hermannskogel":
_toWGS84 = new[] { 653.0, -212.0, 449 };
_spheroid = new Spheroid(Proj4Ellipsoids.Bessel_1841);
_description = "Hermannskogel";
_datumtype = DatumTypes.Param3;
break;
case "ire65":
_toWGS84 = new[] { 482.530, -130.569, 564.557, -1.042, -.214, -.631, 8.15 };
_spheroid = new Spheroid(Proj4Ellipsoids.AiryModified);
_description = "Ireland 1965";
_datumtype = DatumTypes.Param7;
break;
case "nzgd49":
_toWGS84 = new[] { 59.47, -5.04, 187.44, 0.47, -0.1, 1.024, -4.5993 };
_spheroid = new Spheroid(Proj4Ellipsoids.International_1909);
_description = "New Zealand";
_datumtype = DatumTypes.Param7;
break;
case "osgb36":
_toWGS84 = new[] { 446.448, -125.157, 542.060, 0.1502, 0.2470, 0.8421, -20.4894 };
_spheroid = new Spheroid(Proj4Ellipsoids.Airy_1830);
_description = "Airy 1830";
_datumtype = DatumTypes.Param7;
break;
}
}
private void AssignStandardDatum(string datumName)
{
string id = datumName.ToLower();
switch (id)
{
case "wgs84":
_toWGS84 = new double[] { 0, 0, 0 };
_spheroid = new Spheroid(Proj4Ellipsoids.WGS_1984);
_description = "WGS 1984";
_datumtype = DatumTypes.WGS84;
break;
case "ggrs87":
_toWGS84 = new[] { -199.87, 74.79, 246.62 };
_spheroid = new Spheroid(Proj4Ellipsoids.GRS_1980);
_description = "Greek Geodetic Reference System 1987";
_datumtype = DatumTypes.Param3;
break;
case "nad83":
_toWGS84 = new double[] { 0, 0, 0 };
_spheroid = new Spheroid(Proj4Ellipsoids.GRS_1980);
_description = "North American Datum 1983";
_datumtype = DatumTypes.WGS84;
break;
case "nad27":
_nadGrids = new[] { "@conus", "@alaska", "@ntv2_0.gsb", "@ntv1_can.dat" };
_spheroid = new Spheroid(Proj4Ellipsoids.Clarke_1866);
_description = "North American Datum 1927";
_datumtype = DatumTypes.GridShift;
break;
case "potsdam":
_toWGS84 = new[] { 606.0, 23.0, 413.0 };
_spheroid = new Spheroid(Proj4Ellipsoids.Bessel_1841);
_description = "Potsdam Rauenberg 1950 DHDN";
_datumtype = DatumTypes.Param3;
break;
case "carthage":
_toWGS84 = new[] { -263.0, 6, 413 };
_spheroid = new Spheroid(Proj4Ellipsoids.ClarkeModified_1880);
_description = "Carthage 1934 Tunisia";
_datumtype = DatumTypes.Param3;
break;
case "hermannskogel":
_toWGS84 = new[] { 653.0, -212.0, 449 };
_spheroid = new Spheroid(Proj4Ellipsoids.Bessel_1841);
_description = "Hermannskogel";
_datumtype = DatumTypes.Param3;
break;
case "ire65":
_toWGS84 = new[] { 482.530, -130.569, 564.557, -1.042, -.214, -.631, 8.15 };
_spheroid = new Spheroid(Proj4Ellipsoids.AiryModified);
_description = "Ireland 1965";
_datumtype = DatumTypes.Param7;
break;
case "nzgd49":
_toWGS84 = new[] { 59.47, -5.04, 187.44, 0.47, -0.1, 1.024, -4.5993 };
_spheroid = new Spheroid(Proj4Ellipsoids.International_1909);
_description = "New Zealand";
_datumtype = DatumTypes.Param7;
break;
case "osgb36":
_toWGS84 = new[] { 446.448, -125.157, 542.060, 0.1502, 0.2470, 0.8421, -20.4894 };
_spheroid = new Spheroid(Proj4Ellipsoids.Airy_1830);
_description = "Airy 1830";
_datumtype = DatumTypes.Param7;
break;
}
}
