| 1 | /*
|
|---|
| 2 | *+
|
|---|
| 3 | * Name:
|
|---|
| 4 | * palAddet
|
|---|
| 5 |
|
|---|
| 6 | * Purpose:
|
|---|
| 7 | * Add the E-terms to a pre IAU 1976 mean place
|
|---|
| 8 |
|
|---|
| 9 | * Language:
|
|---|
| 10 | * Starlink ANSI C
|
|---|
| 11 |
|
|---|
| 12 | * Type of Module:
|
|---|
| 13 | * Library routine
|
|---|
| 14 |
|
|---|
| 15 | * Invocation:
|
|---|
| 16 | * void palAddet ( double rm, double dm, double eq,
|
|---|
| 17 | * double *rc, double *dc );
|
|---|
| 18 |
|
|---|
| 19 | * Arguments:
|
|---|
| 20 | * rm = double (Given)
|
|---|
| 21 | * RA without E-terms (radians)
|
|---|
| 22 | * dm = double (Given)
|
|---|
| 23 | * Dec without E-terms (radians)
|
|---|
| 24 | * eq = double (Given)
|
|---|
| 25 | * Besselian epoch of mean equator and equinox
|
|---|
| 26 | * rc = double * (Returned)
|
|---|
| 27 | * RA with E-terms included (radians)
|
|---|
| 28 | * dc = double * (Returned)
|
|---|
| 29 | * Dec with E-terms included (radians)
|
|---|
| 30 |
|
|---|
| 31 | * Description:
|
|---|
| 32 | * Add the E-terms (elliptic component of annual aberration)
|
|---|
| 33 | * to a pre IAU 1976 mean place to conform to the old
|
|---|
| 34 | * catalogue convention.
|
|---|
| 35 |
|
|---|
| 36 | * Authors:
|
|---|
| 37 | * PTW: Pat Wallace (STFC)
|
|---|
| 38 | * TIMJ: Tim Jenness (JAC, Hawaii)
|
|---|
| 39 | * {enter_new_authors_here}
|
|---|
| 40 |
|
|---|
| 41 | * Notes:
|
|---|
| 42 | * Most star positions from pre-1984 optical catalogues (or
|
|---|
| 43 | * derived from astrometry using such stars) embody the
|
|---|
| 44 | * E-terms. If it is necessary to convert a formal mean
|
|---|
| 45 | * place (for example a pulsar timing position) to one
|
|---|
| 46 | * consistent with such a star catalogue, then the RA,Dec
|
|---|
| 47 | * should be adjusted using this routine.
|
|---|
| 48 |
|
|---|
| 49 | * See Also:
|
|---|
| 50 | * Explanatory Supplement to the Astronomical Ephemeris,
|
|---|
| 51 | * section 2D, page 48.
|
|---|
| 52 |
|
|---|
| 53 | * History:
|
|---|
| 54 | * 2012-02-12(TIMJ):
|
|---|
| 55 | * Initial version with documentation taken from Fortran SLA
|
|---|
| 56 | * Adapted with permission from the Fortran SLALIB library.
|
|---|
| 57 | * {enter_further_changes_here}
|
|---|
| 58 |
|
|---|
| 59 | * Copyright:
|
|---|
| 60 | * Copyright (C) 1999 Rutherford Appleton Laboratory
|
|---|
| 61 | * Copyright (C) 2012 Science and Technology Facilities Council.
|
|---|
| 62 | * All Rights Reserved.
|
|---|
| 63 |
|
|---|
| 64 | * Licence:
|
|---|
| 65 | * This program is free software: you can redistribute it and/or
|
|---|
| 66 | * modify it under the terms of the GNU Lesser General Public
|
|---|
| 67 | * License as published by the Free Software Foundation, either
|
|---|
| 68 | * version 3 of the License, or (at your option) any later
|
|---|
| 69 | * version.
|
|---|
| 70 | *
|
|---|
| 71 | * This program is distributed in the hope that it will be useful,
|
|---|
| 72 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|---|
| 73 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|---|
| 74 | * GNU Lesser General Public License for more details.
|
|---|
| 75 | *
|
|---|
| 76 | * You should have received a copy of the GNU Lesser General
|
|---|
| 77 | * License along with this program. If not, see
|
|---|
| 78 | * <http://www.gnu.org/licenses/>.
|
|---|
| 79 |
|
|---|
| 80 | * Bugs:
|
|---|
| 81 | * {note_any_bugs_here}
|
|---|
| 82 | *-
|
|---|
| 83 | */
|
|---|
| 84 |
|
|---|
| 85 | #include "pal.h"
|
|---|
| 86 | #include "pal1sofa.h"
|
|---|
| 87 |
|
|---|
| 88 | void palAddet ( double rm, double dm, double eq, double *rc, double *dc ) {
|
|---|
| 89 | double a[3]; /* The E-terms */
|
|---|
| 90 | double v[3];
|
|---|
| 91 | int i;
|
|---|
| 92 |
|
|---|
| 93 | /* Note the preference for IAU routines */
|
|---|
| 94 |
|
|---|
| 95 | /* Retrieve the E-terms */
|
|---|
| 96 | palEtrms( eq, a );
|
|---|
| 97 |
|
|---|
| 98 | /* Spherical to Cartesian */
|
|---|
| 99 | eraS2c( rm, dm, v );
|
|---|
| 100 |
|
|---|
| 101 | /* Include the E-terms */
|
|---|
| 102 | for (i=0; i<3; i++) {
|
|---|
| 103 | v[i] += a[i];
|
|---|
| 104 | }
|
|---|
| 105 |
|
|---|
| 106 | /* Cartesian to spherical */
|
|---|
| 107 | eraC2s( v, rc, dc );
|
|---|
| 108 |
|
|---|
| 109 | /* Bring RA into conventional range */
|
|---|
| 110 | *rc = eraAnp( *rc );
|
|---|
| 111 |
|
|---|
| 112 | }
|
|---|
