/// <summary>
/// The constructor receives the ellipsoid parameters and sets
/// the corresponding state variables. If any errors occur, an
/// exception is thrown with a description of the error.
/// </summary>
/// <param name="ellipsoidSemiMajorAxis">Semi-major axis of ellipsoid in meters</param>
/// <param name="ellipsoidFlattening">Flattening of ellipsoid</param>
/// <param name="ellipsoidCode">2-letter code for ellipsoid</param>
public MGRS(double ellipsoidSemiMajorAxis, double ellipsoidFlattening, string ellipsoidCode)
{
double inv_f = 1 / ellipsoidFlattening;
string errorStatus = "";
if (ellipsoidSemiMajorAxis <= 0.0)
{ /* Semi-major axis must be greater than zero */
errorStatus += ErrorMessages.semiMajorAxis;
}
if ((inv_f < 250) || (inv_f > 350))
{ /* Inverse flattening must be between 250 and 350 */
errorStatus += ErrorMessages.ellipsoidFlattening;
}
if (errorStatus.Length > 0)
{
throw new ArgumentException(errorStatus);
}
this.semiMajorAxis = ellipsoidSemiMajorAxis;
this.flattening = ellipsoidFlattening;
this.ellipsoidCode = ellipsoidCode;
ups = new UPS(this.semiMajorAxis, this.flattening);
utm = new UTM(this.semiMajorAxis, this.flattening, 0);
}
public MGRSorUSNGCoordinates fromUTM(UTMCoordinates utmCoordinates, double longitude, double latitude, long precision)
{
/*
* The function fromUTM calculates an MGRS coordinate string
* based on the zone, latitude, easting and northing.
*
* zone : Zone number (input)
* hemisphere : Hemisphere (input)
* longitude : Longitude in radians (input)
* latitude : Latitude in radians (input)
* easting : Easting (input)
* northing : Northing (input)
* precision : Precision (input)
* MGRSString : MGRS coordinate string (output)
*/
double pattern_offset = 0.0; /* Pattern offset for 3rd letter */
double grid_northing = 0.0; /* Northing used to derive 3rd letter of MGRS */
long ltr2_low_value = 0; /* 2nd letter range - low number */
long ltr2_high_value = 0; /* 2nd letter range - high number */
int[] letters = new int[3]; /* Number location of 3 letters in alphabet */
int zoneOverride = 0;
int natural_zone = 0;
long zone = utmCoordinates.zone;
char hemisphere = utmCoordinates.hemisphere;
double easting = utmCoordinates.easting;
double northing = utmCoordinates.northing;
getLatitudeLetter(latitude, ref letters[0]);
easting = Math.Round(easting);
//Check if the point is within it's natural zone
//If it is not, put it there
if (longitude < Math.PI)
{
natural_zone = (int)(31 + ((longitude) / _6));
}
else
{
natural_zone = (int)(((longitude) / _6) - 29);
}
if (natural_zone > 60)
{
natural_zone = 1;
}
if (zone != natural_zone)
{ // reconvert to override zone
UTM utmOverride = new UTM(semiMajorAxis, flattening, natural_zone);
UTMCoordinates utmCoordinatesOverride = utmOverride.convertFromGeodetic(new GeodeticCoordinates(CoordinateType.Enum.geodetic, longitude, latitude));
zone = utmCoordinatesOverride.zone;
hemisphere = utmCoordinatesOverride.hemisphere;
easting = utmCoordinatesOverride.easting;
northing = utmCoordinatesOverride.northing;
}
easting = Math.Round(easting);
/* UTM special cases */
if (letters[0] == LETTER_V) // V latitude band
{
if ((zone == 31) && (easting >= _500000))
{
zoneOverride = 32; // extension of zone 32V
}
}
else if (letters[0] == LETTER_X)
{
if ((zone == 32) && (easting < _500000)) // extension of zone 31X
{
zoneOverride = 31;
}
else if (((zone == 32) && (easting >= _500000)) || // western extension of zone 33X
((zone == 34) && (easting < _500000))) // eastern extension of zone 33X
{
zoneOverride = 33;
}
else if (((zone == 34) && (easting >= _500000)) || // western extension of zone 35X
((zone == 36) && (easting < _500000))) // eastern extension of zone 35X
{
zoneOverride = 35;
}
else if ((zone == 36) && (easting >= _500000)) // western extension of zone 37X
{
zoneOverride = 37;
}
}
if (zoneOverride != 0)
{ // reconvert to override zone
UTM utmOverride = new UTM(semiMajorAxis, flattening, zoneOverride);
UTMCoordinates utmCoordinatesOverride = utmOverride.convertFromGeodetic(new GeodeticCoordinates(CoordinateType.Enum.geodetic, longitude, latitude));
zone = utmCoordinatesOverride.zone;
hemisphere = utmCoordinatesOverride.hemisphere;
easting = utmCoordinatesOverride.easting;
northing = utmCoordinatesOverride.northing;
}
easting = Math.Round(easting);
northing = Math.Round(northing);
double divisor = Math.Pow(10.0, (5.0 - precision));
easting = (long)(easting / divisor) * divisor;
northing = (long)(northing / divisor) * divisor;
if (latitude <= 0.0 && northing == 1.0e7)
{
latitude = 0.0;
northing = 0.0;
}
getGridValues(zone, ref ltr2_low_value, ref ltr2_high_value, ref pattern_offset);
grid_northing = northing;
while (grid_northing >= TWOMIL)
{
grid_northing = grid_northing - TWOMIL;
}
grid_northing = grid_northing + pattern_offset;
if (grid_northing >= TWOMIL)
{
grid_northing = grid_northing - TWOMIL;
}
letters[2] = (int)(grid_northing / ONEHT);
if (letters[2] > LETTER_H)
{
letters[2] = letters[2] + 1;
}
if (letters[2] > LETTER_N)
{
letters[2] = letters[2] + 1;
}
letters[1] = (int)(ltr2_low_value + ((long)(easting / ONEHT) - 1));
if ((ltr2_low_value == LETTER_J) && (letters[1] > LETTER_N))
{
letters[1] = letters[1] + 1;
}
return new MGRSorUSNGCoordinates(CoordinateType.Enum.militaryGridReferenceSystem, makeMGRSString(zone, letters, easting, northing, precision));
}
public MGRS()
{
//this.CoordSys.getEllipsoidParameters(ref this.semiMajorAxis, ref this.flattening);
this.ups = new UPS(this.semiMajorAxis, this.flattening);
this.utm = new UTM(this.semiMajorAxis, this.flattening, 0);
}
