gc2gde¶
- erfa.gc2gde(a, f, xyz)[source]¶
Transform geocentric coordinates to geodetic for a reference ellipsoid of specified form.
- Parameters:
- adouble array
- fdouble array
- xyzdouble array
- Returns:
- elongdouble array
- phidouble array
- heightdouble array
Notes
Wraps ERFA function
eraGc2gde
. The ERFA documentation is:- - - - - - - - - - e r a G c 2 g d e - - - - - - - - - - Transform geocentric coordinates to geodetic for a reference ellipsoid of specified form. Given: a double equatorial radius (Notes 2,4) f double flattening (Note 3) xyz double[3] geocentric vector (Note 4) Returned: elong double longitude (radians, east +ve) phi double latitude (geodetic, radians) height double height above ellipsoid (geodetic, Note 4) Returned (function value): int status: 0 = OK -1 = illegal f -2 = illegal a Notes: 1) This function is based on the GCONV2H Fortran subroutine by Toshio Fukushima (see reference). 2) The equatorial radius, a, can be in any units, but meters is the conventional choice. 3) The flattening, f, is (for the Earth) a value around 0.00335, i.e. around 1/298. 4) The equatorial radius, a, and the geocentric vector, xyz, must be given in the same units, and determine the units of the returned height, height. 5) If an error occurs (status < 0), elong, phi and height are unchanged. 6) The inverse transformation is performed in the function eraGd2gce. 7) The transformation for a standard ellipsoid (such as ERFA_WGS84) can more conveniently be performed by calling eraGc2gd, which uses a numerical code to identify the required A and F values. Reference: Fukushima, T., "Transformation from Cartesian to geodetic coordinates accelerated by Halley's method", J.Geodesy (2006) 79: 689-693 This revision: 2021 May 11 Copyright (C) 2013-2023, NumFOCUS Foundation. Derived, with permission, from the SOFA library. See notes at end of file.