gc2gd.c

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#include "erfa.h"

int eraGc2gd ( int n, double xyz[3],
               double *elong, double *phi, double *height )
/*
**  - - - - - - - - -
**   e r a G c 2 g d
**  - - - - - - - - -
**
**  Transform geocentric coordinates to geodetic using the specified
**  reference ellipsoid.
**
**  Given:
**     n       int        ellipsoid identifier (Note 1)
**     xyz     double[3]  geocentric vector (Note 2)
**
**  Returned:
**     elong   double     longitude (radians, east +ve, Note 3)
**     phi     double     latitude (geodetic, radians, Note 3)
**     height  double     height above ellipsoid (geodetic, Notes 2,3)
**
**  Returned (function value):
**            int         status:  0 = OK
**                                -1 = illegal identifier (Note 3)
**                                -2 = internal error (Note 3)
**
**  Notes:
**
**  1) The identifier n is a number that specifies the choice of
**     reference ellipsoid.  The following are supported:
**
**        n    ellipsoid
**
**        1     ERFA_WGS84
**        2     ERFA_GRS80
**        3     ERFA_WGS72
**
**     The n value has no significance outside the ERFA software.  For
**     convenience, symbols ERFA_WGS84 etc. are defined in erfam.h.
**
**  2) The geocentric vector (xyz, given) and height (height, returned)
**     are in meters.
**
**  3) An error status -1 means that the identifier n is illegal.  An
**     error status -2 is theoretically impossible.  In all error cases,
**     all three results are set to -1e9.
**
**  4) The inverse transformation is performed in the function eraGd2gc.
**
**  Called:
**     eraEform     Earth reference ellipsoids
**     eraGc2gde    geocentric to geodetic transformation, general
**
**  Copyright (C) 2013-2015, NumFOCUS Foundation.
**  Derived, with permission, from the SOFA library.  See notes at end of file.
*/
{
   int j;
   double a, f;

/* Obtain reference ellipsoid parameters. */
   j = eraEform ( n, &a, &f );

/* If OK, transform x,y,z to longitude, geodetic latitude, height. */
   if ( j == 0 ) {
      j = eraGc2gde ( a, f, xyz, elong, phi, height );
      if ( j < 0 ) j = -2;
   }

/* Deal with any errors. */
   if ( j < 0 ) {
      *elong = -1e9;
      *phi = -1e9;
      *height = -1e9;
   }

/* Return the status. */
   return j;

}
/*----------------------------------------------------------------------
**  
**  
**  Copyright (C) 2013-2015, NumFOCUS Foundation.
**  All rights reserved.
**  
**  This library is derived, with permission, from the International
**  Astronomical Union's "Standards of Fundamental Astronomy" library,
**  available from http://www.iausofa.org.
**  
**  The ERFA version is intended to retain identical functionality to
**  the SOFA library, but made distinct through different function and
**  file names, as set out in the SOFA license conditions.  The SOFA
**  original has a role as a reference standard for the IAU and IERS,
**  and consequently redistribution is permitted only in its unaltered
**  state.  The ERFA version is not subject to this restriction and
**  therefore can be included in distributions which do not support the
**  concept of "read only" software.
**  
**  Although the intent is to replicate the SOFA API (other than
**  replacement of prefix names) and results (with the exception of
**  bugs;  any that are discovered will be fixed), SOFA is not
**  responsible for any errors found in this version of the library.
**  
**  If you wish to acknowledge the SOFA heritage, please acknowledge
**  that you are using a library derived from SOFA, rather than SOFA
**  itself.
**  
**  
**  TERMS AND CONDITIONS
**  
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**  modification, are permitted provided that the following conditions
**  are met:
**  
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**  
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