rspfDpt rspfPolarStereoProjection::forward(const rspfGpt &latLon)const
{
double easting = 0.0;
double northing = 0.0;
rspfGpt gpt = latLon;
if (theDatum)
{
if (theDatum->code() != latLon.datum()->code())
{
gpt.changeDatum(theDatum); // Shift to our datum.
}
}
Convert_Geodetic_To_Polar_Stereographic(gpt.latr(),
gpt.lonr(),
&easting,
&northing);
return rspfDpt(easting, northing);
}
long Convert_Geodetic_To_UPS ( double Latitude,
double Longitude,
char *Hemisphere,
double *Easting,
double *Northing)
{
/*
* The function Convert_Geodetic_To_UPS 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.
*
* Latitude : Latitude in radians (input)
* Longitude : Longitude in radians (input)
* Hemisphere : Hemisphere either 'N' or 'S' (output)
* Easting : Easting/X in meters (output)
* Northing : Northing/Y in meters (output)
*/
double tempEasting, tempNorthing;
long Error_Code = UPS_NO_ERROR;
if ((Latitude < -MAX_LAT) || (Latitude > MAX_LAT))
{ /* latitude out of range */
Error_Code |= UPS_LAT_ERROR;
}
if ((Latitude < 0) && (Latitude > MIN_SOUTH_LAT))
Error_Code |= UPS_LAT_ERROR;
if ((Latitude >= 0) && (Latitude < MIN_NORTH_LAT))
Error_Code |= UPS_LAT_ERROR;
if ((Longitude < -PI) || (Longitude > (2 * PI)))
{ /* slam out of range */
Error_Code |= UPS_LON_ERROR;
}
if (!Error_Code)
{ /* no errors */
if (Latitude < 0)
{
UPS_Origin_Latitude = -MAX_ORIGIN_LAT;
*Hemisphere = 'S';
}
else
{
UPS_Origin_Latitude = MAX_ORIGIN_LAT;
*Hemisphere = 'N';
}
Set_Polar_Stereographic_Parameters( UPS_a,
UPS_f,
UPS_Origin_Latitude,
UPS_Origin_Longitude,
false_easting,
false_northing);
Convert_Geodetic_To_Polar_Stereographic(Latitude,
Longitude,
&tempEasting,
&tempNorthing);
UPS_Easting = UPS_False_Easting + tempEasting;
UPS_Northing = UPS_False_Northing + tempNorthing;
*Easting = UPS_Easting;
*Northing = UPS_Northing;
} /* END of if(!Error_Code) */
return (Error_Code);
} /* END OF Convert_Geodetic_To_UPS */
/* FUNCTIONS
*
*/
long rspfPolarStereoProjection::Set_Polar_Stereographic_Parameters (double a,
double f,
double Latitude_of_True_Scale,
double Longitude_Down_from_Pole,
double False_Easting,
double False_Northing)
{ /* BEGIN Set_Polar_Stereographic_Parameters */
/*
* The function Set_Polar_Stereographic_Parameters receives the ellipsoid
* parameters and Polar Stereograpic projection parameters as inputs, and
* sets the corresponding state variables. If any errors occur, error
* code(s) are returned by the function, otherwise POLAR_NO_ERROR is returned.
*
* a : Semi-major axis of ellipsoid, in meters (input)
* f : Flattening of ellipsoid (input)
* Latitude_of_True_Scale : Latitude of true scale, in radians (input)
* Longitude_Down_from_Pole : Longitude down from pole, in radians (input)
* False_Easting : Easting (X) at center of projection, in meters (input)
* False_Northing : Northing (Y) at center of projection, in meters (input)
*/
double es2;
double slat, clat;
double essin;
double one_PLUS_es, one_MINUS_es;
double pow_es;
double temp;
const double epsilon = 1.0e-2;
long Error_Code = POLAR_NO_ERROR;
if (!Error_Code)
{ /* no errors */
Polar_a = a;
two_Polar_a = 2.0 * Polar_a;
Polar_f = f;
if (Longitude_Down_from_Pole > M_PI)
Longitude_Down_from_Pole -= TWO_PI;
if (Latitude_of_True_Scale < 0)
{
Southern_Hemisphere = 1;
Polar_Origin_Lat = -Latitude_of_True_Scale;
Polar_Origin_Long = -Longitude_Down_from_Pole;
}
else
{
Southern_Hemisphere = 0;
Polar_Origin_Lat = Latitude_of_True_Scale;
Polar_Origin_Long = Longitude_Down_from_Pole;
}
Polar_False_Easting = False_Easting;
Polar_False_Northing = False_Northing;
es2 = 2 * Polar_f - Polar_f * Polar_f;
es = sqrt(es2);
es_OVER_2 = es / 2.0;
if (fabs(fabs(Polar_Origin_Lat) - PI_OVER_2) > 1.0e-10)
{
slat = sin(Polar_Origin_Lat);
essin = es * slat;
pow_es = POLAR_POW(essin);
clat = cos(Polar_Origin_Lat);
mc = clat / sqrt(1.0 - essin * essin);
Polar_a_mc = Polar_a * mc;
tc = tan(PI_Over_4 - Polar_Origin_Lat / 2.0) / pow_es;
}
else
{
one_PLUS_es = 1.0 + es;
one_MINUS_es = 1.0 - es;
e4 = sqrt(pow(one_PLUS_es, one_PLUS_es) * pow(one_MINUS_es, one_MINUS_es));
}
}
/* Calculate Radius */
Convert_Geodetic_To_Polar_Stereographic(0, Polar_Origin_Long,
&temp, &Polar_Delta_Northing);
Polar_Delta_Northing = fabs(Polar_Delta_Northing) + epsilon;
Polar_Delta_Easting = Polar_Delta_Northing;
return (Error_Code);
} /* END OF Set_Polar_Stereographic_Parameters */
long Set_Polar_Stereographic_Parameters (double a,
double f,
double Latitude_of_True_Scale,
double Longitude_Down_from_Pole,
double False_Easting,
double False_Northing)
{ /* BEGIN Set_Polar_Stereographic_Parameters */
/*
* The function Set_Polar_Stereographic_Parameters receives the ellipsoid
* parameters and Polar Stereograpic projection parameters as inputs, and
* sets the corresponding state variables. If any errors occur, error
* code(s) are returned by the function, otherwise POLAR_NO_ERROR is returned.
*
* a : Semi-major axis of ellipsoid, in meters (input)
* f : Flattening of ellipsoid (input)
* Latitude_of_True_Scale : Latitude of true scale, in radians (input)
* Longitude_Down_from_Pole : Longitude down from pole, in radians (input)
* False_Easting : Easting (X) at center of projection, in meters (input)
* False_Northing : Northing (Y) at center of projection, in meters (input)
*/
double es2;
double slat, clat;
double essin;
double one_PLUS_es, one_MINUS_es;
double pow_es;
double temp, temp_northing = 0;
double inv_f = 1 / f;
double mc;
// const double epsilon = 1.0e-2;
long Error_Code = POLAR_NO_ERROR;
if (a <= 0.0)
{ /* Semi-major axis must be greater than zero */
Error_Code |= POLAR_A_ERROR;
}
if ((inv_f < 250) || (inv_f > 350))
{ /* Inverse flattening must be between 250 and 350 */
Error_Code |= POLAR_INV_F_ERROR;
}
if ((Latitude_of_True_Scale < -PI_OVER_2) || (Latitude_of_True_Scale > PI_OVER_2))
{ /* Origin Latitude out of range */
Error_Code |= POLAR_ORIGIN_LAT_ERROR;
}
if ((Longitude_Down_from_Pole < -PI) || (Longitude_Down_from_Pole > TWO_PI))
{ /* Origin Longitude out of range */
Error_Code |= POLAR_ORIGIN_LON_ERROR;
}
if (!Error_Code)
{ /* no errors */
Polar_a = a;
two_Polar_a = 2.0 * Polar_a;
Polar_f = f;
if (Longitude_Down_from_Pole > PI)
Longitude_Down_from_Pole -= TWO_PI;
if (Latitude_of_True_Scale < 0)
{
Southern_Hemisphere = 1;
Polar_Origin_Lat = -Latitude_of_True_Scale;
Polar_Origin_Long = -Longitude_Down_from_Pole;
}
else
{
Southern_Hemisphere = 0;
Polar_Origin_Lat = Latitude_of_True_Scale;
Polar_Origin_Long = Longitude_Down_from_Pole;
}
Polar_False_Easting = False_Easting;
Polar_False_Northing = False_Northing;
es2 = 2 * Polar_f - Polar_f * Polar_f;
es = sqrt(es2);
es_OVER_2 = es / 2.0;
if (fabs(fabs(Polar_Origin_Lat) - PI_OVER_2) > 1.0e-10)
{
slat = sin(Polar_Origin_Lat);
essin = es * slat;
pow_es = POLAR_POW(essin);
clat = cos(Polar_Origin_Lat);
mc = clat / sqrt(1.0 - essin * essin);
Polar_a_mc = Polar_a * mc;
tc = tan(PI_Over_4 - Polar_Origin_Lat / 2.0) / pow_es;
}
else
{
one_PLUS_es = 1.0 + es;
one_MINUS_es = 1.0 - es;
e4 = sqrt(pow(one_PLUS_es, one_PLUS_es) * pow(one_MINUS_es, one_MINUS_es));
}
/* Calculate Radius */
Convert_Geodetic_To_Polar_Stereographic(0, Longitude_Down_from_Pole,
&temp, &temp_northing);
Polar_Delta_Northing = temp_northing;
if(Polar_False_Northing)
Polar_Delta_Northing -= Polar_False_Northing;
if (Polar_Delta_Northing < 0)
Polar_Delta_Northing = -Polar_Delta_Northing;
Polar_Delta_Northing *= 1.01;
Polar_Delta_Easting = Polar_Delta_Northing;
/* Polar_Delta_Easting = temp_northing;
if(Polar_False_Easting)
Polar_Delta_Easting -= Polar_False_Easting;
if (Polar_Delta_Easting < 0)
Polar_Delta_Easting = -Polar_Delta_Easting;
Polar_Delta_Easting *= 1.01;*/
}
return (Error_Code);
} /* END OF Set_Polar_Stereographic_Parameters */
