diff options
Diffstat (limited to 'ast/erfa/gc2gde.c')
| -rw-r--r-- | ast/erfa/gc2gde.c | 208 |
1 files changed, 0 insertions, 208 deletions
diff --git a/ast/erfa/gc2gde.c b/ast/erfa/gc2gde.c deleted file mode 100644 index 43ed61d..0000000 --- a/ast/erfa/gc2gde.c +++ /dev/null @@ -1,208 +0,0 @@ -#include "erfa.h" - -int eraGc2gde ( double a, double f, double xyz[3], - double *elong, double *phi, double *height ) -/* -** - - - - - - - - - - -** 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 -** -** Copyright (C) 2013-2016, NumFOCUS Foundation. -** Derived, with permission, from the SOFA library. See notes at end of file. -*/ -{ - double aeps2, e2, e4t, ec2, ec, b, x, y, z, p2, absz, p, s0, pn, zc, - c0, c02, c03, s02, s03, a02, a0, a03, d0, f0, b0, s1, - cc, s12, cc2; - - -/* ------------- */ -/* Preliminaries */ -/* ------------- */ - -/* Validate ellipsoid parameters. */ - if ( f < 0.0 || f >= 1.0 ) return -1; - if ( a <= 0.0 ) return -2; - -/* Functions of ellipsoid parameters (with further validation of f). */ - aeps2 = a*a * 1e-32; - e2 = (2.0 - f) * f; - e4t = e2*e2 * 1.5; - ec2 = 1.0 - e2; - if ( ec2 <= 0.0 ) return -1; - ec = sqrt(ec2); - b = a * ec; - -/* Cartesian components. */ - x = xyz[0]; - y = xyz[1]; - z = xyz[2]; - -/* Distance from polar axis squared. */ - p2 = x*x + y*y; - -/* Longitude. */ - *elong = p2 > 0.0 ? atan2(y, x) : 0.0; - -/* Unsigned z-coordinate. */ - absz = fabs(z); - -/* Proceed unless polar case. */ - if ( p2 > aeps2 ) { - - /* Distance from polar axis. */ - p = sqrt(p2); - - /* Normalization. */ - s0 = absz / a; - pn = p / a; - zc = ec * s0; - - /* Prepare Newton correction factors. */ - c0 = ec * pn; - c02 = c0 * c0; - c03 = c02 * c0; - s02 = s0 * s0; - s03 = s02 * s0; - a02 = c02 + s02; - a0 = sqrt(a02); - a03 = a02 * a0; - d0 = zc*a03 + e2*s03; - f0 = pn*a03 - e2*c03; - - /* Prepare Halley correction factor. */ - b0 = e4t * s02 * c02 * pn * (a0 - ec); - s1 = d0*f0 - b0*s0; - cc = ec * (f0*f0 - b0*c0); - - /* Evaluate latitude and height. */ - *phi = atan(s1/cc); - s12 = s1 * s1; - cc2 = cc * cc; - *height = (p*cc + absz*s1 - a * sqrt(ec2*s12 + cc2)) / - sqrt(s12 + cc2); - } else { - - /* Exception: pole. */ - *phi = ERFA_DPI / 2.0; - *height = absz - b; - } - -/* Restore sign of latitude. */ - if ( z < 0 ) *phi = -*phi; - -/* OK status. */ - return 0; - -} -/*---------------------------------------------------------------------- -** -** -** Copyright (C) 2013-2016, 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 -** -** Redistribution and use in source and binary forms, with or without -** modification, are permitted provided that the following conditions -** are met: -** -** 1 Redistributions of source code must retain the above copyright -** notice, this list of conditions and the following disclaimer. -** -** 2 Redistributions in binary form must reproduce the above copyright -** notice, this list of conditions and the following disclaimer in -** the documentation and/or other materials provided with the -** distribution. -** -** 3 Neither the name of the Standards Of Fundamental Astronomy Board, -** the International Astronomical Union nor the names of its -** contributors may be used to endorse or promote products derived -** from this software without specific prior written permission. -** -** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS -** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE -** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, -** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, -** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; -** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER -** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT -** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN -** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE -** POSSIBILITY OF SUCH DAMAGE. -** -*/ |