/// <summary>
/// Create a new MGRS reference object from the given UTM reference. It is
/// assumed that this MGRS reference represents a point using the GRS 1980,
/// International or WGS84 ellipsoids. It is assumed that the UTMRef object is
/// valid.
/// </summary>
/// <param name="utm">A UTM reference.</param>
/// <param name="isBessel">true if the parameters represent an MGRS reference using the
/// Bessel 1841 ellipsoid; false is the parameters represent an MGRS
/// reference using the GRS 1980, International or WGS84 ellipsoids.</param>
public MGRSRef(UTMRef utm, bool isBessel = false) : base(utm.Datum)
{
int lngZone = utm.LngZone;
int set = ((lngZone - 1) % 6) + 1;
int eId =
(int)Math.Floor(utm.Easting / 100000.0) + (8 * ((set - 1) % 3));
int nId = (int)Math.Floor((utm.Northing % 2000000) / 100000.0);
if (eId > 8)
{
eId++; // Offset for no I character
}
if (eId > 14)
{
eId++; // Offset for no O character
}
char eIDc = (char)(eId + 64);
// Northing ID offset for sets 2, 4 and 6
if (set % 2 == 0)
{
nId += 5;
}
if (isBessel)
{
nId += 10;
}
if (nId > 19)
{
nId -= 20;
}
char nIDc = NorthingIDs[nId];
UtmZoneNumber = lngZone;
UtmZoneChar = utm.LatZone;
EastingId = eIDc;
NorthingId = nIDc;
Easting = (int)Math.Round(utm.Easting) % 100000;
Northing = (int)Math.Round(utm.Northing) % 100000;
Precision = Precision.Precision1M;
_isBessel = isBessel;
}
/// <summary>
/// Create a new MGRS reference object from the given UTM reference. It is
/// assumed that this MGRS reference represents a point using the GRS 1980,
/// International or WGS84 ellipsoids. It is assumed that the UTMRef object is
/// valid.
/// </summary>
/// <param name="utm">A UTM reference.</param>
/// <param name="isBessel">true if the parameters represent an MGRS reference using the
/// Bessel 1841 ellipsoid; false is the parameters represent an MGRS
/// reference using the GRS 1980, International or WGS84 ellipsoids.</param>
public MGRSRef(UTMRef utm, bool isBessel) : base(utm.Datum)
{
int lngZone = utm.LngZone;
int set = ((lngZone - 1) % 6) + 1;
int eID =
(int)Math.Floor(utm.Easting / 100000.0) + (8 * ((set - 1) % 3));
int nID = (int)Math.Floor((utm.Northing % 2000000) / 100000.0);
if (eID > 8)
{
eID++; // Offset for no I character
}
if (eID > 14)
{
eID++; // Offset for no O character
}
char eIDc = (char)(eID + 64);
// Northing ID offset for sets 2, 4 and 6
if (set % 2 == 0)
{
nID += 5;
}
if (isBessel)
{
nID += 10;
}
if (nID > 19)
{
nID -= 20;
}
char nIDc = northingIDs[nID];
this.utmZoneNumber = lngZone;
this.utmZoneChar = utm.LatZone;
this.eastingID = eIDc;
this.northingID = nIDc;
this.easting = (int)Math.Round(utm.Easting) % 100000;
this.northing = (int)Math.Round(utm.Northing) % 100000;
this.precision = Precision.Precision1M;
this.isBessel = isBessel;
}
/// <summary>
/// Create a new MGRS reference object from the given UTM reference. It is
/// assumed that this MGRS reference represents a point using the GRS 1980,
/// International or WGS84 ellipsoids. It is assumed that the UTMRef object is
/// valid.
/// </summary>
/// <param name="utm">A UTM reference.</param>
/// <param name="isBessel">true if the parameters represent an MGRS reference using the
/// Bessel 1841 ellipsoid; false is the parameters represent an MGRS
/// reference using the GRS 1980, International or WGS84 ellipsoids.</param>
public MGRSRef(UTMRef utm, bool isBessel)
: base(utm.Datum)
{
int lngZone = utm.LngZone;
int set = ((lngZone - 1) % 6) + 1;
int eID =
(int) Math.Floor(utm.Easting / 100000.0) + (8 * ((set - 1) % 3));
int nID = (int) Math.Floor((utm.Northing % 2000000) / 100000.0);
if (eID > 8)
eID++; // Offset for no I character
if (eID > 14)
eID++; // Offset for no O character
char eIDc = (char) (eID + 64);
// Northing ID offset for sets 2, 4 and 6
if (set % 2 == 0) {
nID += 5;
}
if (isBessel) {
nID += 10;
}
if (nID > 19) {
nID -= 20;
}
char nIDc = northingIDs[nID];
this.utmZoneNumber = lngZone;
this.utmZoneChar = utm.LatZone;
this.eastingID = eIDc;
this.northingID = nIDc;
this.easting = (int) Math.Round(utm.Easting) % 100000;
this.northing = (int) Math.Round(utm.Northing) % 100000;
this.precision = Precision.Precision1M;
this.isBessel = isBessel;
}
/// <summary>
/// Create a new MGRS reference object from the given UTM reference. It is
/// assumed that the UTMRef object is valid.
/// </summary>
/// <param name="utm">A UTM reference.</param>
public MGRSRef(UTMRef utm)
: this(utm, false)
{
}
/// <summary>
/// Convert this latitude and longitude to an MGRS reference.
/// </summary>
/// <returns>The converted MGRS reference</returns>
public MGRSRef ToMGRSRef()
{
UTMRef utm = ToUtmRef();
return(new MGRSRef(utm));
}
/// <summary>
/// Convert this latitude and longitude to a UTM reference.
/// </summary>
/// <returns>The converted UTM reference.</returns>
/// <exception cref="NotDefinedOnUtmGridException">
/// If an attempt is made to convert a LatLng that falls outside the
/// area covered by the UTM grid. The UTM grid is only defined for
/// latitudes south of 84°N and north of 80°S.</exception>
public UTMRef ToUtmRef()
{
if (Latitude < -80 || Latitude > 84)
{
throw new NotDefinedOnUtmGridException("Latitude (" + Latitude
+ ") falls outside the UTM grid.");
}
if (Longitude == 180.0)
{
Longitude = -180.0;
}
const double utmF0 = 0.9996;
double a = Datum.ReferenceEllipsoid.SemiMajorAxis;
double eSquared = Datum.ReferenceEllipsoid.EccentricitySquared;
double longitude = Longitude;
double latitude = Latitude;
double latitudeRad = latitude * (Math.PI / 180.0);
double longitudeRad = longitude * (Math.PI / 180.0);
int longitudeZone = (int)Math.Floor((longitude + 180.0) / 6.0) + 1;
// Special zone for Norway
if (latitude >= 56.0 && latitude < 64.0 && longitude >= 3.0 &&
longitude < 12.0)
{
longitudeZone = 32;
}
// Special zones for Svalbard
if (latitude >= 72.0 && latitude < 84.0)
{
if (longitude >= 0.0 && longitude < 9.0)
{
longitudeZone = 31;
}
else if (longitude >= 9.0 && longitude < 21.0)
{
longitudeZone = 33;
}
else if (longitude >= 21.0 && longitude < 33.0)
{
longitudeZone = 35;
}
else if (longitude >= 33.0 && longitude < 42.0)
{
longitudeZone = 37;
}
}
double longitudeOrigin = (longitudeZone - 1) * 6 - 180 + 3;
double longitudeOriginRad = longitudeOrigin * (Math.PI / 180.0);
char utmZone = UTMRef.GetUTMLatitudeZoneLetter(latitude);
double ePrimeSquared = (eSquared) / (1 - eSquared);
double n = a
/ Math.Sqrt(1 - eSquared * Math.Sin(latitudeRad)
* Math.Sin(latitudeRad));
double t = Math.Tan(latitudeRad) * Math.Tan(latitudeRad);
double c = ePrimeSquared * Math.Cos(latitudeRad) * Math.Cos(latitudeRad);
double A = Math.Cos(latitudeRad) * (longitudeRad - longitudeOriginRad);
double m = a
* ((1 - eSquared / 4 - 3 * eSquared * eSquared / 64 - 5 * eSquared
* eSquared * eSquared / 256)
* latitudeRad
- (3 * eSquared / 8 + 3 * eSquared * eSquared / 32 + 45 * eSquared
* eSquared * eSquared / 1024)
* Math.Sin(2 * latitudeRad)
+ (15 * eSquared * eSquared / 256 + 45 * eSquared * eSquared
* eSquared / 1024) * Math.Sin(4 * latitudeRad) - (35 * eSquared
* eSquared * eSquared / 3072)
* Math.Sin(6 * latitudeRad));
double utmEasting = (utmF0
* n
* (A + (1 - t + c) * Math.Pow(A, 3.0) / 6 + (5 - 18 * t + t * t + 72
* c - 58 * ePrimeSquared)
* Math.Pow(A, 5.0) / 120) + 500000.0);
double utmNorthing = (utmF0 * (m + n
* Math.Tan(latitudeRad)
* (A * A / 2 + (5 - t + (9 * c) + (4 * c * c)) * Math.Pow(A, 4.0) / 24 + (61
- (58 * t) + (t * t) + (600 * c) - (330 * ePrimeSquared))
* Math.Pow(A, 6.0) / 720)));
// Adjust for the southern hemisphere
if (latitude < 0)
{
utmNorthing += 10000000.0;
}
return(new UTMRef(longitudeZone, utmZone, utmEasting, utmNorthing, Datum));
}
/// <summary>
/// Create a new MGRS reference object from the given UTM reference. It is
/// assumed that the UTMRef object is valid.
/// </summary>
/// <param name="utm">A UTM reference.</param>
public MGRSRef(UTMRef utm) : this(utm, false)
{
}
