private static Coordinate MGRS_Polar_ToLatLong(MilitaryGridReferenceSystem mgrs, EagerLoad el)
{
//WORKING
bool isNorth = true;
if (mgrs.latZone.ToUpper() == "A" || mgrs.latZone.ToUpper() == "B")
{
isNorth = false;
}
string latz = mgrs.LatZone;
string digraph = mgrs.Digraph;
char eltr = digraph[0];
char nltr = digraph[1];
string digraphLettersE;
if (!isNorth)
{
digraphLettersE = "KLPQRSTUXYZABCFGH";
}
else
{
digraphLettersE = "RSTUXYZABCFGHJ";
}
string digraphLettersN;
if (!isNorth)
{
digraphLettersN = "VWXYBCDEFGHJKLMNPQRSTUVWXYZ";
}
else
{
digraphLettersN = "ABCDEFGHJKLMNP";
}
string digraphLettersAll = "";
for (int lt = 1; lt < 31; lt++)
{
digraphLettersAll += digraphLettersN;
}
var eidx = digraphLettersE.IndexOf(eltr);
//Offsets are set due to less Easting Identifiers.
//North has 4 less than S
double offset = 9;
if (isNorth)
{
offset = 13;
}
if (mgrs.latZone == "B" && eidx < offset && mgrs.easting != 0)
{
eidx += 18;
}
double subbase = eidx + offset;
var ebase = 100000 * subbase;
var latBand = digraphLettersE.IndexOf(latz);
var latBandLow = 8 * latBand - 96;
var latBandHigh = 8 * latBand - 88;
if (!isNorth)
{
latBandLow = -90;
latBandHigh = -80;
}
else
{
latBandLow = 84;
latBandHigh = 90;
}
var lowLetter = Math.Floor(100 + 1.11 * latBandLow);
var highLetter = Math.Round(100 + 1.11 * latBandHigh);
string latBandLetters = null;
int l = Convert.ToInt32(lowLetter);
int h = Convert.ToInt32(highLetter + 7);
if (mgrs.LongZone / 2.0 == Math.Floor(mgrs.LongZone / 2.0))
{
latBandLetters = digraphLettersAll.Substring(l + 5, h + 5).ToString();
}
else
{
latBandLetters = digraphLettersAll.Substring(l, h).ToString();
}
//North offset + 4 due to lower band count.
double nOffset = 13;
if (!isNorth)
{
nOffset = 10;
}
else
{
latBandLetters = digraphLettersN;
}
int index = latBandLetters.IndexOf(nltr);
if (index == -1 && nltr == 'A')
{
index -= 1;
} //ALPHA PATCH
//int subset = 0;
//if ((latz == "Y" || latz == "Z") && (nOffset+index)>25 && (ebase> 2100000 || ebase<2000000) && ebase!= 2000000) { subset = -14; }
var nbase = 100000 * (index + nOffset);
var x = ebase + mgrs.Easting;
var y = nbase + mgrs.Northing;
if (mgrs.systemType != MGRS_Type.MGRS_Polar)
{
if (y > 10000000)
{
y = y - 10000000;
}
if (nbase >= 10000000)
{
y = nbase + mgrs.northing - 10000000;
}
}
// Debug.WriteLine("MGRS {0} {1}", x, y);
UniversalTransverseMercator utm = new UniversalTransverseMercator(mgrs.LatZone, mgrs.LongZone, x, y, true);
utm.equatorial_radius = mgrs.equatorialRadius;
utm.inverse_flattening = mgrs.inverseFlattening;
Coordinate c = UniversalTransverseMercator.ConvertUTMtoLatLong(utm, el);
c.Set_Datum(mgrs.equatorialRadius, mgrs.inverseFlattening);
return(c);
}
private static Coordinate UTMtoLatLong(double x, double y, double zone, double equatorialRadius, double flattening, EagerLoad el)
{
//x easting
//y northing
//http://home.hiwaay.net/~taylorc/toolbox/geography/geoutm.html
double phif, Nf, Nfpow, nuf2, ep2, tf, tf2, tf4, cf;
double x1frac, x2frac, x3frac, x4frac, x5frac, x6frac, x7frac, x8frac;
double x2poly, x3poly, x4poly, x5poly, x6poly, x7poly, x8poly;
double sm_a = equatorialRadius;
double sm_b = equatorialRadius * (1 - (1.0 / flattening)); //Polar Radius
/* Get the value of phif, the footpoint latitude. */
phif = FootpointLatitude(y, equatorialRadius, flattening);
/* Precalculate ep2 */
ep2 = (Math.Pow(sm_a, 2.0) - Math.Pow(sm_b, 2.0))
/ Math.Pow(sm_b, 2.0);
/* Precalculate cos (phif) */
cf = Math.Cos(phif);
/* Precalculate nuf2 */
nuf2 = ep2 * Math.Pow(cf, 2.0);
/* Precalculate Nf and initialize Nfpow */
Nf = Math.Pow(sm_a, 2.0) / (sm_b * Math.Sqrt(1 + nuf2));
Nfpow = Nf;
/* Precalculate tf */
tf = Math.Tan(phif);
tf2 = tf * tf;
tf4 = tf2 * tf2;
/* Precalculate fractional coefficients for x**n in the equations
* below to simplify the expressions for latitude and longitude. */
x1frac = 1.0 / (Nfpow * cf);
Nfpow *= Nf; /* now equals Nf**2) */
x2frac = tf / (2.0 * Nfpow);
Nfpow *= Nf; /* now equals Nf**3) */
x3frac = 1.0 / (6.0 * Nfpow * cf);
Nfpow *= Nf; /* now equals Nf**4) */
x4frac = tf / (24.0 * Nfpow);
Nfpow *= Nf; /* now equals Nf**5) */
x5frac = 1.0 / (120.0 * Nfpow * cf);
Nfpow *= Nf; /* now equals Nf**6) */
x6frac = tf / (720.0 * Nfpow);
Nfpow *= Nf; /* now equals Nf**7) */
x7frac = 1.0 / (5040.0 * Nfpow * cf);
Nfpow *= Nf; /* now equals Nf**8) */
x8frac = tf / (40320.0 * Nfpow);
/* Precalculate polynomial coefficients for x**n.
* -- x**1 does not have a polynomial coefficient. */
x2poly = -1.0 - nuf2;
x3poly = -1.0 - 2 * tf2 - nuf2;
x4poly = 5.0 + 3.0 * tf2 + 6.0 * nuf2 - 6.0 * tf2 * nuf2
- 3.0 * (nuf2 * nuf2) - 9.0 * tf2 * (nuf2 * nuf2);
x5poly = 5.0 + 28.0 * tf2 + 24.0 * tf4 + 6.0 * nuf2 + 8.0 * tf2 * nuf2;
x6poly = -61.0 - 90.0 * tf2 - 45.0 * tf4 - 107.0 * nuf2
+ 162.0 * tf2 * nuf2;
x7poly = -61.0 - 662.0 * tf2 - 1320.0 * tf4 - 720.0 * (tf4 * tf2);
x8poly = 1385.0 + 3633.0 * tf2 + 4095.0 * tf4 + 1575 * (tf4 * tf2);
/* Calculate latitude */
double nLat = phif + x2frac * x2poly * (x * x)
+ x4frac * x4poly * Math.Pow(x, 4.0)
+ x6frac * x6poly * Math.Pow(x, 6.0)
+ x8frac * x8poly * Math.Pow(x, 8.0);
/* Calculate longitude */
double nLong = zone + x1frac * x
+ x3frac * x3poly * Math.Pow(x, 3.0)
+ x5frac * x5poly * Math.Pow(x, 5.0)
+ x7frac * x7poly * Math.Pow(x, 7.0);
double dLat = RadToDeg(nLat);
double dLong = RadToDeg(nLong);
if (dLat > 90)
{
dLat = 90;
}
if (dLat < -90)
{
dLat = -90;
}
if (dLong > 180)
{
dLong = 180;
}
if (dLong < -180)
{
dLong = -180;
}
Coordinate c = new Coordinate(dLat, dLong, el, equatorialRadius, flattening);
c.Set_Datum(equatorialRadius, flattening);
return(c);
}
/// <summary>
/// Creates a Coordinate object from an MGRS/NATO UTM Coordinate
/// </summary>
/// <param name="mgrs">MilitaryGridReferenceSystem</param>
/// <param name="eagerLoad">EagerLoad</param>
/// <returns>Coordinate object</returns>
/// <example>
/// The following example creates (converts to) a geodetic Coordinate object based on a MGRS object.
/// <code>
/// MilitaryGridReferenceSystem mgrs = new MilitaryGridReferenceSystem("N", 21, "SA", 66037, 61982);
/// Coordinate c = MilitaryGridReferenceSystem.MGRStoLatLong(mgrs, new EagerLoad(false));
/// Console.WriteLine(c); //N 0º 33' 35.988" W 60º 0' 0.01"
/// </code>
/// </example>
public static Coordinate MGRStoLatLong(MilitaryGridReferenceSystem mgrs, EagerLoad eagerLoad)
{
if (mgrs.systemType == MGRS_Type.MGRS_Polar)
{
return(MGRS_Polar_ToLatLong(mgrs, eagerLoad));
}
string latz = mgrs.LatZone;
string digraph = mgrs.Digraph;
char eltr = digraph[0];
char nltr = digraph[1];
string digraphLettersE = "ABCDEFGHJKLMNPQRSTUVWXYZ";
string digraphLettersN = "ABCDEFGHJKLMNPQRSTUV";
string digraphLettersAll = "";
for (int lt = 1; lt < 25; lt++)
{
digraphLettersAll += digraphLettersN;
}
var eidx = digraphLettersE.IndexOf(eltr);
var pbase = 100000;
double fl = Math.Floor(Convert.ToDouble(eidx) / 8);
double subbase = 1 + eidx - 8 * fl;
var ebase = pbase * subbase;
var latBand = digraphLettersE.IndexOf(latz);
var latBandLow = 8 * latBand - 96;
var latBandHigh = 8 * latBand - 88;
if (latBand < 2)
{
latBandLow = -90;
latBandHigh = -80;
}
else if (latBand == 21)
{
latBandLow = 72;
latBandHigh = 84;
}
else if (latBand > 21)
{
latBandLow = 84;
latBandHigh = 90;
}
var lowLetter = Math.Floor(100 + 1.11 * latBandLow);
var highLetter = Math.Round(100 + 1.11 * latBandHigh);
string latBandLetters = null;
int l = Convert.ToInt32(lowLetter);
int h = Convert.ToInt32(highLetter);
if (mgrs.LongZone / 2.0 == Math.Floor(mgrs.LongZone / 2.0))
{
latBandLetters = digraphLettersAll.Substring(l + 5, h + 5).ToString();
}
else
{
latBandLetters = digraphLettersAll.Substring(l, h).ToString();
}
var nbase = 100000 * (lowLetter + latBandLetters.IndexOf(nltr));
//latBandLetters.IndexOf(nltr) value causing incorrect Northing below -80
var x = ebase + mgrs.Easting;
var y = nbase + mgrs.Northing;
if (mgrs.systemType != MGRS_Type.MGRS_Polar)
{
if (y > 10000000)
{
y = y - 10000000;
}
if (nbase >= 10000000)
{
y = nbase + mgrs.northing - 10000000;
}
}
UniversalTransverseMercator utm = new UniversalTransverseMercator(mgrs.LatZone, mgrs.LongZone, x, y, true);
utm.equatorial_radius = mgrs.equatorialRadius;
utm.inverse_flattening = mgrs.inverseFlattening;
Coordinate c = UniversalTransverseMercator.ConvertUTMtoLatLong(utm, eagerLoad);
c.Set_Datum(mgrs.equatorialRadius, mgrs.inverseFlattening);
return(c);
}
/// <summary>
/// Creates a Coordinate object from an MGRS/NATO UTM Coordinate
/// </summary>
/// <param name="mgrs">MilitaryGridReferenceSystem</param>
/// <returns>Coordinate object</returns>
public static Coordinate MGRStoLatLong(MilitaryGridReferenceSystem mgrs)
{
string latz = mgrs.LatZone;
string digraph = mgrs.Digraph;
char eltr = digraph[0];
char nltr = digraph[1];
string digraphLettersE = "ABCDEFGHJKLMNPQRSTUVWXYZ";
string digraphLettersN = "ABCDEFGHJKLMNPQRSTUV";
string digraphLettersAll = "";
for (int lt = 1; lt < 25; lt++)
{
digraphLettersAll += "ABCDEFGHJKLMNPQRSTUV";
}
var eidx = digraphLettersE.IndexOf(eltr);
var nidx = digraphLettersN.IndexOf(nltr);
if (mgrs.LongZone / 2.0 == Math.Floor(mgrs.LongZone / 2.0))
{
nidx -= 5; // correction for even numbered zones
}
var ebase = 100000 * (1 + eidx - 8 * Math.Floor(Convert.ToDouble(eidx) / 8));
var latBand = digraphLettersE.IndexOf(latz);
var latBandLow = 8 * latBand - 96;
var latBandHigh = 8 * latBand - 88;
if (latBand < 2)
{
latBandLow = -90;
latBandHigh = -80;
}
else if (latBand == 21)
{
latBandLow = 72;
latBandHigh = 84;
}
else if (latBand > 21)
{
latBandLow = 84;
latBandHigh = 90;
}
var lowLetter = Math.Floor(100 + 1.11 * latBandLow);
var highLetter = Math.Round(100 + 1.11 * latBandHigh);
string latBandLetters = null;
int l = Convert.ToInt32(lowLetter);
int h = Convert.ToInt32(highLetter);
if (mgrs.LongZone / 2.0 == Math.Floor(mgrs.LongZone / 2.0))
{
latBandLetters = digraphLettersAll.Substring(l + 5, h + 5).ToString();
}
else
{
latBandLetters = digraphLettersAll.Substring(l, h).ToString();
}
var nbase = 100000 * (lowLetter + latBandLetters.IndexOf(nltr));
var x = ebase + mgrs.Easting;
var y = nbase + mgrs.Northing;
if (y > 10000000)
{
y = y - 10000000;
}
if (nbase >= 10000000)
{
y = nbase + mgrs.northing - 10000000;
}
var southern = nbase < 10000000;
UniversalTransverseMercator utm = new UniversalTransverseMercator(mgrs.LatZone, mgrs.LongZone, x, y);
utm.equatorial_radius = mgrs.equatorialRadius;
utm.inverse_flattening = mgrs.inverseFlattening;
Coordinate c = UniversalTransverseMercator.ConvertUTMtoLatLong(utm);
c.Set_Datum(mgrs.equatorialRadius, mgrs.inverseFlattening);
// Coordinate nc = new Coordinate(c.Latitude.ToDouble(), c.Longitude.ToDouble());
return(c);
}
