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era.gc2gd.md

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eraGc2gd

[rv, elong, phi, height] = ERFA.gc2gd( n, xyz)

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.

  1. The geocentric vector (xyz, given) and height (height, returned) are in meters.

  2. 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.

  3. The inverse transformation is performed in the function eraGd2gc.

Called:

   eraEform     Earth reference ellipsoids
   eraGc2gde    geocentric to geodetic transformation, general

This revision: 2021 May 11

Copyright (C) 2013-2021, NumFOCUS Foundation. Derived, with permission, from the SOFA library.