/// <summary> Converts UTM coords to lat/long. Equations from USGS Bulletin 1532 </summary>
public Lat_Long UTMtoLL(double UTMEasting, double UTMNorthing)
{
Lat_Long theseLL = new Lat_Long();
if ((savedDatumIndex < 0 || savedDatumIndex > 10))
{
return(theseLL);
}
Ellipsoid_Shapes thisShape = GetEllipsoidShape(savedDatumIndex);
double k0 = 0.9996;
double equatRad = thisShape.equatorialRadius;
double eccSquared = thisShape.eccentricitySquared;
double e1 = (1 - Math.Pow((1 - eccSquared), 0.5)) / (1 + Math.Pow((1 - eccSquared), 0.5));
double douDimble;
int NorthernHemisphere = 0; // 1 for northern hemisphere, 0 for southern
double x = UTMEasting - 500000.0; ////remove 500,000 meter offset for longitude
double y = UTMNorthing;
// //if((*UTMZoneLetter - 'N') >= 0)
if (hemisphere == "Northern")
{
NorthernHemisphere = 1; ////point is in northern hemisphere
}
else
{
NorthernHemisphere = 0; ////point is in southern hemisphere
y -= 10000000.0; ////remove 10,000,000 meter offset used for southern hemisphere
}
double longOrigin = (UTMZoneNumber - 1) * 6 - 180 + 3; ////+3 puts origin in middle of zone
double eccPrimeSquared = (eccSquared) / (1 - eccSquared);
double M = y / k0;
double mu = M / (equatRad * (1 - eccSquared / 4 - 3 * eccSquared * eccSquared / 64 - 5 * eccSquared * eccSquared * eccSquared / 256));
double phi1Rad = mu + (3 * e1 / 2 - 27 * e1 * e1 * e1 / 32) * Math.Sin(2 * mu)
+ (21 * e1 * e1 / 16 - 55 * e1 * e1 * e1 * e1 / 32) * Math.Sin(4 * mu)
+ (151 * e1 * e1 * e1 / 96) * Math.Sin(6 * mu);
double phi1 = phi1Rad * rad2deg;
double N1 = equatRad / Math.Pow((1 - eccSquared * Math.Sin(phi1Rad) * Math.Sin(phi1Rad)), 0.5);
double T1 = Math.Tan(phi1Rad) * Math.Tan(phi1Rad);
double C1 = eccPrimeSquared * Math.Cos(phi1Rad) * Math.Cos(phi1Rad);
double R1 = equatRad * (1 - eccSquared) / Math.Pow(1 - eccSquared * Math.Sin(phi1Rad) * Math.Sin(phi1Rad), 1.5);
double D = x / (N1 * k0);
theseLL.latitude = phi1Rad - (N1 * Math.Tan(phi1Rad) / R1) * (D * D / 2 - (5 + 3 * T1 + 10 * C1 - 4 * C1 * C1 - 9 * eccPrimeSquared) * D * D * D * D / 24
+ (61 + 90 * T1 + 298 * C1 + 45 * T1 * T1 - 252 * eccPrimeSquared - 3 * C1 * C1) * D * D * D * D * D * D / 720);
theseLL.latitude = theseLL.latitude * rad2deg;
theseLL.longitude = (D - (1 + 2 * T1 + C1) * D * D * D / 6 + (5 - 2 * C1 + 28 * T1 - 3 * C1 * C1 + 8 * eccPrimeSquared + 24 * T1 * T1)
* D * D * D * D * D / 120) / Math.Cos(phi1Rad);
theseLL.longitude = longOrigin + theseLL.longitude * rad2deg;
return(theseLL);
}
/// <summary> Returns ellipse shape based on index </summary>
public Ellipsoid_Shapes GetEllipsoidShape(int ellipsoidIndex)
{
Ellipsoid_Shapes thisShape = new Ellipsoid_Shapes();
if (ellipsoidIndex == 0) // NAD83/WGS84 (Global)
{
thisShape.equatorialRadius = 6378137;
thisShape.eccentricitySquared = 0.00669438;
}
else if (ellipsoidIndex == 1) // GRS 80 (US)
{
thisShape.equatorialRadius = 6378137;
thisShape.eccentricitySquared = 0.00669438;
}
else if (ellipsoidIndex == 2) // WGS72 (NASA, DOD)
{
thisShape.equatorialRadius = 6378135;
thisShape.eccentricitySquared = 0.006694324;
}
else if (ellipsoidIndex == 3) // Australian 1965
{
thisShape.equatorialRadius = 6378160;
thisShape.eccentricitySquared = 0.006694548;
}
else if (ellipsoidIndex == 4) // Krasovsky 1940 (Russia)
{
thisShape.equatorialRadius = 6378245;
thisShape.eccentricitySquared = 0.006693427;
}
else if (ellipsoidIndex == 5) // International (1924) -Hayford (1909) (Europe)
{
thisShape.equatorialRadius = 6378388;
thisShape.eccentricitySquared = 0.006722684;
}
else if (ellipsoidIndex == 6) // Clake 1880 (France, Africa)
{
thisShape.equatorialRadius = 6378249.1;
thisShape.eccentricitySquared = 0.006803488;
}
else if (ellipsoidIndex == 7) // NAD27/Clarke 1866 (North America)
{
thisShape.equatorialRadius = 6378206.4;
thisShape.eccentricitySquared = 0.006768658;
}
else if (ellipsoidIndex == 8) // Airy 1830 (Great Britain)
{
thisShape.equatorialRadius = 6377563.4;
thisShape.eccentricitySquared = 0.006670544;
}
else if (ellipsoidIndex == 9) // Bessel 1841 (Central Europe, Chile, Indonesia)
{
thisShape.equatorialRadius = 6377397.2;
thisShape.eccentricitySquared = 0.006674375;
}
else if (ellipsoidIndex == 10) // Everest 1830 (South Asia)
{
thisShape.equatorialRadius = 6377276.3;
thisShape.eccentricitySquared = 0.006637837;
}
return(thisShape);
}
/// <summary> Converts lat/long to UTM coords. Equations from USGS Bulletin 1532 </summary>
public UTM_coords LLtoUTM(double thisLat, double thisLong)
{
UTM_coords theseUTMcoords = new UTM_coords();
if ((savedDatumIndex < 0 || savedDatumIndex > 10))
{
return(theseUTMcoords);
}
Ellipsoid_Shapes thisEllip = GetEllipsoidShape(savedDatumIndex);
double equatRad = thisEllip.equatorialRadius;
double eccSquared = thisEllip.eccentricitySquared;
double k0 = 0.9996f;
// //Make sure the longitude is between -180.00 .. 179.9
double longTemp = (thisLong + 180) - (int)((thisLong + 180) / 360) * 360 - 180; //// -180.00 .. 179.9;
double latRad = thisLat * deg2rad;
double longRad = longTemp * deg2rad;
// double longOriginRad;
if (UTMZoneNumber == -999)
{
UTMZoneNumber = (int)((longTemp + 180) / 6) + 1;
}
if ((thisLat >= 56.0 && thisLat < 64.0 && longTemp >= 3.0 && longTemp < 12.0))
{
UTMZoneNumber = 32;
}
//// Special zones for Svalbard
if ((thisLat >= 72.0 && thisLat < 84.0))
{
if ((longTemp >= 0.0 && longTemp < 9.0))
{
UTMZoneNumber = 31;
}
else if ((longTemp >= 9.0 && longTemp < 21.0))
{
UTMZoneNumber = 33;
}
else if ((longTemp >= 21.0 && longTemp < 33.0))
{
UTMZoneNumber = 35;
}
else if ((longTemp >= 33.0 && longTemp < 42.0))
{
UTMZoneNumber = 37;
}
}
double longOrigin = (UTMZoneNumber - 1) * 6 - 180 + 3; ////+3 puts origin in middle of zone
double longOriginRad = longOrigin * deg2rad;
////compute the UTM Zone from the latitude and longitude
theseUTMcoords.UTMZoneNumber = UTMZoneNumber;
theseUTMcoords.hemisphere = hemisphere;
double eccPrimeSquared = (eccSquared) / (1 - eccSquared);
double N = equatRad / Math.Pow((1 - eccSquared * Math.Sin(latRad) * Math.Sin(latRad)), 0.5);
double T = Math.Tan(latRad) * Math.Tan(latRad);
double C = eccPrimeSquared * Math.Cos(latRad) * Math.Cos(latRad);
double A = Math.Cos(latRad) * (longRad - longOriginRad);
double M = equatRad * ((1.0f - eccSquared / 4.0f - 3.0f * eccSquared * eccSquared / 64.0f - 5.0f * eccSquared * eccSquared * eccSquared / 256.0f) * latRad
- (3 * eccSquared / 8 + 3 * eccSquared * eccSquared / 32 + 45 * eccSquared * eccSquared * eccSquared / 1024) * Math.Sin(2 * latRad)
+ (15 * eccSquared * eccSquared / 256 + 45 * eccSquared * eccSquared * eccSquared / 1024) * Math.Sin(4 * latRad)
- (35 * eccSquared * eccSquared * eccSquared / 3072) * Math.Sin(6 * latRad));
theseUTMcoords.UTMEasting = k0 * N * (A + (1 - T + C) * A * A * A / 6 + (5 - 18 * T + T * T + 72 * C - 58 * eccPrimeSquared) * A * A * A * A * A / 120) + 500000.0;
theseUTMcoords.UTMNorthing = k0 * (M + N * Math.Tan(latRad) * (A * A / 2 + (5 - T + 9 * C + 4 * C * C) * A * A * A * A / 24 + (61 - 58 * T + T * T + 600 * C - 330 * eccPrimeSquared) * A * A * A * A * A * A / 720));
if ((thisLat < 0))
{
theseUTMcoords.UTMNorthing += 10000000.0; ////10000000 meter offset for southern hemisphere
}
return(theseUTMcoords);
}
