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Diffstat (limited to 'ast/erfa/ldn.c')
| -rw-r--r-- | ast/erfa/ldn.c | 183 |
1 files changed, 0 insertions, 183 deletions
diff --git a/ast/erfa/ldn.c b/ast/erfa/ldn.c deleted file mode 100644 index 5ad0a50..0000000 --- a/ast/erfa/ldn.c +++ /dev/null @@ -1,183 +0,0 @@ -#include "erfa.h" - -void eraLdn(int n, eraLDBODY b[], double ob[3], double sc[3], - double sn[3]) -/*+ -** - - - - - - - -** e r a L d n -** - - - - - - - -** -** For a star, apply light deflection by multiple solar-system bodies, -** as part of transforming coordinate direction into natural direction. -** -** Given: -** n int number of bodies (note 1) -** b eraLDBODY[n] data for each of the n bodies (Notes 1,2): -** bm double mass of the body (solar masses, Note 3) -** dl double deflection limiter (Note 4) -** pv [2][3] barycentric PV of the body (au, au/day) -** ob double[3] barycentric position of the observer (au) -** sc double[3] observer to star coord direction (unit vector) -** -** Returned: -** sn double[3] observer to deflected star (unit vector) -** -** 1) The array b contains n entries, one for each body to be -** considered. If n = 0, no gravitational light deflection will be -** applied, not even for the Sun. -** -** 2) The array b should include an entry for the Sun as well as for -** any planet or other body to be taken into account. The entries -** should be in the order in which the light passes the body. -** -** 3) In the entry in the b array for body i, the mass parameter -** b[i].bm can, as required, be adjusted in order to allow for such -** effects as quadrupole field. -** -** 4) The deflection limiter parameter b[i].dl is phi^2/2, where phi is -** the angular separation (in radians) between star and body at -** which limiting is applied. As phi shrinks below the chosen -** threshold, the deflection is artificially reduced, reaching zero -** for phi = 0. Example values suitable for a terrestrial -** observer, together with masses, are as follows: -** -** body i b[i].bm b[i].dl -** -** Sun 1.0 6e-6 -** Jupiter 0.00095435 3e-9 -** Saturn 0.00028574 3e-10 -** -** 5) For cases where the starlight passes the body before reaching the -** observer, the body is placed back along its barycentric track by -** the light time from that point to the observer. For cases where -** the body is "behind" the observer no such shift is applied. If -** a different treatment is preferred, the user has the option of -** instead using the eraLd function. Similarly, eraLd can be used -** for cases where the source is nearby, not a star. -** -** 6) The returned vector sn is not normalized, but the consequential -** departure from unit magnitude is always negligible. -** -** 7) The arguments sc and sn can be the same array. -** -** 8) For efficiency, validation is omitted. The supplied masses must -** be greater than zero, the position and velocity vectors must be -** right, and the deflection limiter greater than zero. -** -** Reference: -** -** Urban, S. & Seidelmann, P. K. (eds), Explanatory Supplement to -** the Astronomical Almanac, 3rd ed., University Science Books -** (2013), Section 7.2.4. -** -** Called: -** eraCp copy p-vector -** eraPdp scalar product of two p-vectors -** eraPmp p-vector minus p-vector -** eraPpsp p-vector plus scaled p-vector -** eraPn decompose p-vector into modulus and direction -** eraLd light deflection by a solar-system body -** -** Copyright (C) 2013-2016, NumFOCUS Foundation. -** Derived, with permission, from the SOFA library. See notes at end of file. -*/ -{ -/* Light time for 1 AU (days) */ - const double CR = ERFA_AULT/ERFA_DAYSEC; - - int i; - double v[3], dt, ev[3], em, e[3]; - - -/* Star direction prior to deflection. */ - eraCp(sc, sn); - -/* Body by body. */ - for ( i = 0; i < n; i++ ) { - - /* Body to observer vector at epoch of observation (au). */ - eraPmp ( ob, b[i].pv[0], v ); - - /* Minus the time since the light passed the body (days). */ - dt = eraPdp(sn,v) * CR; - - /* Neutralize if the star is "behind" the observer. */ - dt = ERFA_GMIN(dt, 0.0); - - /* Backtrack the body to the time the light was passing the body. */ - eraPpsp(v, -dt, b[i].pv[1], ev); - - /* Body to observer vector as magnitude and direction. */ - eraPn(ev, &em, e); - - /* Apply light deflection for this body. */ - eraLd ( b[i].bm, sn, sn, e, em, b[i].dl, sn ); - - /* Next body. */ - } - -/* Finished. */ - -} -/*---------------------------------------------------------------------- -** -** -** 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. -** -*/ |