/********************************************************************/
/* RSC IDENTIFIER: UPS
*
*
* ABSTRACT
*
* This component provides conversions between geodetic (latitude
* and longitude) coordinates and Universal Polar Stereographic (UPS)
* projection (hemisphere, easting, and northing) coordinates.
*
*
* ERROR HANDLING
*
* This component checks parameters for valid values. If an
* invalid value is found the error code is combined with the
* current error code using the bitwise or. This combining allows
* multiple error codes to be returned. The possible error codes
* are:
*
* UPS_NO_ERROR : No errors occurred in function
* UPS_LAT_ERROR : Latitude outside of valid range
* (North Pole: 83.5 to 90,
* South Pole: -79.5 to -90)
* UPS_LON_ERROR : Longitude outside of valid range
* (-180 to 360 degrees)
* UPS_HEMISPHERE_ERROR : Invalid hemisphere ('N' or 'S')
* UPS_EASTING_ERROR : Easting outside of valid range,
* (0 to 4,000,000m)
* UPS_NORTHING_ERROR : Northing outside of valid range,
* (0 to 4,000,000m)
* UPS_A_ERROR : Semi-major axis less than or equal to zero
* UPS_INV_F_ERROR : Inverse flattening outside of valid range
* (250 to 350)
*
*
* REUSE NOTES
*
* UPS is intended for reuse by any application that performs a Universal
* Polar Stereographic (UPS) projection.
*
*
* REFERENCES
*
* Further information on UPS can be found in the Reuse Manual.
*
* UPS originated from : U.S. Army Topographic Engineering Center
* Geospatial Information Division
* 7701 Telegraph Road
* Alexandria, VA 22310-3864
*
*
* LICENSES
*
* None apply to this component.
*
*
* RESTRICTIONS
*
* UPS has no restrictions.
*
*
* ENVIRONMENT
*
* UPS was tested and certified in the following environments:
*
* 1. Solaris 2.5 with GCC version 2.8.1
* 2. Windows 95 with MS Visual C++ version 6
*
*
* MODIFICATIONS
*
* Date Description
* ---- -----------
* 06-11-95 Original Code
* 03-01-97 Original Code
*
*
*/
package gov.nasa.worldwind.geom.coords;
/**
* Ported to Java from the NGA GeoTrans ups.c and ups.h code
*
* @author Garrett Headley
* @version Feb 12, 2007 4:52:59 PM
*/
public class UPSConverter
{
public static final int UPS_NO_ERROR = 0x0000;
private static final int UPS_LAT_ERROR = 0x0001;
private static final int UPS_LON_ERROR = 0x0002;
public static final int UPS_HEMISPHERE_ERROR = 0x0004;
public static final int UPS_EASTING_ERROR = 0x0008;
public static final int UPS_NORTHING_ERROR = 0x0010;
private static final int UPS_A_ERROR = 0x0020;
private static final int UPS_INV_F_ERROR = 0x0040;
private static final double PI = 3.14159265358979323;
private static final double MAX_LAT = (PI * 90) / 180.0; // 90 degrees in radians
private static final double MIN_NORTH_LAT = 83.5 * PI / 180.0;
private static final double MIN_SOUTH_LAT = -79.5 * PI / 180.0;
private static final double MAX_ORIGIN_LAT = (81.114528 * PI) / 180.0;
private static final double MIN_EAST_NORTH = 0;
private static final double MAX_EAST_NORTH = 4000000;
private static double UPS_Origin_Latitude = MAX_ORIGIN_LAT; /*set default = North Hemisphere */
private static double UPS_Origin_Longitude = 0.0;
/* Ellipsoid Parameters, default to WGS 84 */
private static double UPS_a = 6378137.0; /* Semi-major axis of ellipsoid in meters */
private static double UPS_f = 1 / 298.257223563; /* Flattening of ellipsoid */
private static double UPS_False_Easting = 2000000.0;
private static double UPS_False_Northing = 2000000.0;
private static double false_easting = 0.0;
private static double false_northing = 0.0;
private static double UPS_Easting = 0.0;
private static double UPS_Northing = 0.0;
private static double Easting = 0.0;
private static double Northing = 0.0;
private static char Hemisphere = 'N';
private static double Latitude = 0.0;
private static double Longitude = 0.0;
// This constructor will never be invoked
private UPSConverter()
{
}
/**
* The function SetUPSParameters receives the ellipsoid parameters and sets the corresponding state variables. If
* any errors occur, the error code(s) are returned by the function, otherwise UPS_NO_ERROR is returned.
*
* @param a Semi-major axis of ellipsoid in meters
* @param f Flattening of ellipsoid
* @return error code
*/
public static long SetUPSParameters(double a, double f)
{
double inv_f = 1 / f;
if (a <= 0.0)
{ /* Semi-major axis must be greater than zero */
return UPS_A_ERROR;
}
if ((inv_f < 250) || (inv_f > 350))
{ /* Inverse flattening must be between 250 and 350 */
return UPS_INV_F_ERROR;
}
UPS_a = a;
UPS_f = f;
return (UPS_NO_ERROR);
}
/**
* The function convertGeodeticToUPS converts geodetic (latitude and longitude) coordinates to UPS (hemisphere,
* easting, and northing) coordinates, according to the current ellipsoid parameters. If any errors occur, the error
* code(s) are returned by the function, otherwide UPS_NO_ERROR is returned.
*
* @param latitude Latitude in radians
* @param longitude Longitude in radians
* @return error code
*/
public static long convertGeodeticToUPS(double latitude, double longitude)
{
if ((latitude < -MAX_LAT) || (latitude > MAX_LAT))
{ /* latitude out of range */
return UPS_LAT_ERROR;
}
if ((latitude < 0) && (latitude > MIN_SOUTH_LAT))
return UPS_LAT_ERROR;
if ((latitude >= 0) && (latitude < MIN_NORTH_LAT))
return UPS_LAT_ERROR;
if ((longitude < -PI) || (longitude > (2 * PI)))
{ /* slam out of range */
return UPS_LON_ERROR;
}
if (latitude < 0)
{
UPS_Origin_Latitude = -MAX_ORIGIN_LAT;
Hemisphere = 'S';
} else
{
UPS_Origin_Latitude = MAX_ORIGIN_LAT;
Hemisphere = 'N';
}
PolarConverter.setPolarStereographicParameters(UPS_a, UPS_f,
UPS_Origin_Latitude, UPS_Origin_Longitude,
false_easting, false_northing);
PolarConverter.Convert_Geodetic_To_Polar_Stereographic(latitude, longitude);
UPS_Easting = UPS_False_Easting + PolarConverter.getEasting();
UPS_Northing = UPS_False_Northing + PolarConverter.getNorthing();
Easting = UPS_Easting;
Northing = UPS_Northing;
return UPS_NO_ERROR;
}
/**
* @return Easting/X in meters
*/
public static double getEasting()
{
return Easting;
}
/**
* @return Northing/Y in meters
*/
public static double getNorthing()
{
return Northing;
}
/**
* @return Hemisphere 'N' or 'S'
*/
public static char getHemisphere()
{
return Hemisphere;
}
/**
* The function Convert_UPS_To_Geodetic converts UPS (hemisphere, easting,
* and northing) coordinates to geodetic (latitude and longitude) coordinates
* according to the current ellipsoid parameters. If any errors occur, the
* error code(s) are returned by the function, otherwise UPS_NO_ERROR is
* returned.
*
* @param Hemisphere Hemisphere either 'N' or 'S'
* @param Easting Easting/X in meters
* @param Northing Northing/Y in meters
* @return error code
*/
public static long convertUPSToGeodetic(char Hemisphere, double Easting, double Northing)
{
long Error_Code = UPS_NO_ERROR;
if ((Hemisphere != 'N') && (Hemisphere != 'S'))
Error_Code |= UPS_HEMISPHERE_ERROR;
if ((Easting < MIN_EAST_NORTH) || (Easting > MAX_EAST_NORTH))
Error_Code |= UPS_EASTING_ERROR;
if ((Northing < MIN_EAST_NORTH) || (Northing > MAX_EAST_NORTH))
Error_Code |= UPS_NORTHING_ERROR;
if (Hemisphere =='N')
UPS_Origin_Latitude = MAX_ORIGIN_LAT;
if (Hemisphere =='S')
UPS_Origin_Latitude = -MAX_ORIGIN_LAT;
if (Error_Code == UPS_NO_ERROR)
{ /* no errors */
PolarConverter.setPolarStereographicParameters(UPS_a,
UPS_f,
UPS_Origin_Latitude,
UPS_Origin_Longitude,
UPS_False_Easting,
UPS_False_Northing);
PolarConverter.Convert_Polar_Stereographic_To_Geodetic( Easting, Northing);
Latitude = PolarConverter.getLatitude();
Longitude = PolarConverter.getLongitude();
if ((Latitude < 0) && (Latitude > MIN_SOUTH_LAT))
Error_Code |= UPS_LAT_ERROR;
if ((Latitude >= 0) && (Latitude < MIN_NORTH_LAT))
Error_Code |= UPS_LAT_ERROR;
}
return Error_Code;
}
/**
* @return Latitude in radians.
*/
public static double getLatitude()
{
return Latitude;
}
/**
* @return Longitude in radians.
*/
public static double getLongitude()
{
return Longitude;
}
}