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Diffstat (limited to 'ast/pal/palEtrms.c')
-rw-r--r-- | ast/pal/palEtrms.c | 106 |
1 files changed, 0 insertions, 106 deletions
diff --git a/ast/pal/palEtrms.c b/ast/pal/palEtrms.c deleted file mode 100644 index 4484682..0000000 --- a/ast/pal/palEtrms.c +++ /dev/null @@ -1,106 +0,0 @@ -/* -*+ -* Name: -* palEtrms - -* Purpose: -* Compute the E-terms vector - -* Language: -* Starlink ANSI C - -* Type of Module: -* Library routine - -* Invocation: -* void palEtrms ( double ep, double ev[3] ); - -* Arguments: -* ep = double (Given) -* Besselian epoch -* ev = double [3] (Returned) -* E-terms as (dx,dy,dz) - -* Description: -* Computes the E-terms (elliptic component of annual aberration) -* vector. -* -* Note the use of the J2000 aberration constant (20.49552 arcsec). -* This is a reflection of the fact that the E-terms embodied in -* existing star catalogues were computed from a variety of -* aberration constants. Rather than adopting one of the old -* constants the latest value is used here. -* -* See also: -* - Smith, C.A. et al., 1989. Astr.J. 97, 265. -* - Yallop, B.D. et al., 1989. Astr.J. 97, 274. - -* Authors: -* PTW: Pat Wallace (STFC) -* TIMJ: Tim Jenness (JAC, Hawaii) -* {enter_new_authors_here} - -* History: -* 2012-02-12 (TIMJ): -* Initial version with documentation taken from Fortran SLA -* Adapted with permission from the Fortran SLALIB library. -* {enter_further_changes_here} - -* Copyright: -* Copyright (C) 1996 Rutherford Appleton Laboratory -* Copyright (C) 2012 Science and Technology Facilities Council. -* All Rights Reserved. - -* Licence: -* This program is free software: you can redistribute it and/or -* modify it under the terms of the GNU Lesser General Public -* License as published by the Free Software Foundation, either -* version 3 of the License, or (at your option) any later -* version. -* -* This program is distributed in the hope that it will be useful, -* but WITHOUT ANY WARRANTY; without even the implied warranty of -* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -* GNU Lesser General Public License for more details. -* -* You should have received a copy of the GNU Lesser General -* License along with this program. If not, see -* <http://www.gnu.org/licenses/>. - -* Bugs: -* {note_any_bugs_here} -*- -*/ - -#include "pal.h" -#include "palmac.h" - -void palEtrms ( double ep, double ev[3] ) { - - /* Use the J2000 aberration constant */ - const double ABCONST = 20.49552; - - double t, e, e0, p, ek, cp; - - /* Julian centuries since B1950 */ - t = (ep - 1950.) * .0100002135903; - - /* Eccentricity */ - e = .01673011 - (t * 1.26e-7 + 4.193e-5) * t; - - /* Mean obliquity */ - e0 = (84404.836 - ((t * .00181 + .00319) * t + 46.8495) * t) * - PAL__DAS2R; - - /* Mean longitude of perihelion */ - p = (((t * .012 + 1.65) * t + 6190.67) * t + 1015489.951) * - PAL__DAS2R; - - /* E-terms */ - ek = e * ABCONST * PAL__DAS2R; - cp = cos(p); - ev[0] = ek * sin(p); - ev[1] = -ek * cp * cos(e0); - ev[2] = -ek * cp * sin(e0); - -} |