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#include "sofa.h"
int iauPmsafe(double ra1, double dec1, double pmr1, double pmd1,
double px1, double rv1,
double ep1a, double ep1b, double ep2a, double ep2b,
double *ra2, double *dec2, double *pmr2, double *pmd2,
double *px2, double *rv2)
/*
** - - - - - - - - - -
** i a u P m s a f e
** - - - - - - - - - -
**
** Star proper motion: update star catalog data for space motion, with
** special handling to handle the zero parallax case.
**
** This function is part of the International Astronomical Union's
** SOFA (Standards of Fundamental Astronomy) software collection.
**
** Status: support function.
**
** Given:
** ra1 double right ascension (radians), before
** dec1 double declination (radians), before
** pmr1 double RA proper motion (radians/year), before
** pmd1 double Dec proper motion (radians/year), before
** px1 double parallax (arcseconds), before
** rv1 double radial velocity (km/s, +ve = receding), before
** ep1a double "before" epoch, part A (Note 1)
** ep1b double "before" epoch, part B (Note 1)
** ep2a double "after" epoch, part A (Note 1)
** ep2b double "after" epoch, part B (Note 1)
**
** Returned:
** ra2 double right ascension (radians), after
** dec2 double declination (radians), after
** pmr2 double RA proper motion (radians/year), after
** pmd2 double Dec proper motion (radians/year), after
** px2 double parallax (arcseconds), after
** rv2 double radial velocity (km/s, +ve = receding), after
**
** Returned (function value):
** int status:
** -1 = system error (should not occur)
** 0 = no warnings or errors
** 1 = distance overridden (Note 6)
** 2 = excessive velocity (Note 7)
** 4 = solution didn't converge (Note 8)
** else = binary logical OR of the above warnings
**
** Notes:
**
** 1) The starting and ending TDB epochs ep1a+ep1b and ep2a+ep2b are
** Julian Dates, apportioned in any convenient way between the two
** parts (A and B). For example, JD(TDB)=2450123.7 could be
** expressed in any of these ways, among others:
**
** epNa epNb
**
** 2450123.7 0.0 (JD method)
** 2451545.0 -1421.3 (J2000 method)
** 2400000.5 50123.2 (MJD method)
** 2450123.5 0.2 (date & time method)
**
** The JD method is the most natural and convenient to use in cases
** where the loss of several decimal digits of resolution is
** acceptable. The J2000 method is best matched to the way the
** argument is handled internally and will deliver the optimum
** resolution. The MJD method and the date & time methods are both
** good compromises between resolution and convenience.
**
** 2) In accordance with normal star-catalog conventions, the object's
** right ascension and declination are freed from the effects of
** secular aberration. The frame, which is aligned to the catalog
** equator and equinox, is Lorentzian and centered on the SSB.
**
** The proper motions are the rate of change of the right ascension
** and declination at the catalog epoch and are in radians per TDB
** Julian year.
**
** The parallax and radial velocity are in the same frame.
**
** 3) Care is needed with units. The star coordinates are in radians
** and the proper motions in radians per Julian year, but the
** parallax is in arcseconds.
**
** 4) The RA proper motion is in terms of coordinate angle, not true
** angle. If the catalog uses arcseconds for both RA and Dec proper
** motions, the RA proper motion will need to be divided by cos(Dec)
** before use.
**
** 5) Straight-line motion at constant speed, in the inertial frame, is
** assumed.
**
** 6) An extremely small (or zero or negative) parallax is overridden
** to ensure that the object is at a finite but very large distance,
** but not so large that the proper motion is equivalent to a large
** but safe speed (about 0.1c using the chosen constant). A warning
** status of 1 is added to the status if this action has been taken.
**
** 7) If the space velocity is a significant fraction of c (see the
** constant VMAX in the function iauStarpv), it is arbitrarily set
** to zero. When this action occurs, 2 is added to the status.
**
** 8) The relativistic adjustment carried out in the iauStarpv function
** involves an iterative calculation. If the process fails to
** converge within a set number of iterations, 4 is added to the
** status.
**
** Called:
** iauSeps angle between two points
** iauStarpm update star catalog data for space motion
**
** This revision: 2014 July 1
**
** SOFA release 2020-07-21
**
** Copyright (C) 2020 IAU SOFA Board. See notes at end.
*/
{
/* Minimum allowed parallax (arcsec) */
const double PXMIN = 5e-7;
/* Factor giving maximum allowed transverse speed of about 1% c */
const double F = 326.0;
int jpx, j;
double pm, px1a;
/* Proper motion in one year (radians). */
pm = iauSeps(ra1, dec1, ra1+pmr1, dec1+pmd1);
/* Override the parallax to reduce the chances of a warning status. */
jpx = 0;
px1a = px1;
pm *= F;
if (px1a < pm) {jpx = 1; px1a = pm;}
if (px1a < PXMIN) {jpx = 1; px1a = PXMIN;}
/* Carry out the transformation using the modified parallax. */
j = iauStarpm(ra1, dec1, pmr1, pmd1, px1a, rv1,
ep1a, ep1b, ep2a, ep2b,
ra2, dec2, pmr2, pmd2, px2, rv2);
/* Revise and return the status. */
if ( !(j%2) ) j += jpx;
return j;
/* Finished. */
/*----------------------------------------------------------------------
**
** Copyright (C) 2020
** Standards Of Fundamental Astronomy Board
** of the International Astronomical Union.
**
** =====================
** SOFA Software License
** =====================
**
** NOTICE TO USER:
**
** BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING SIX TERMS AND
** CONDITIONS WHICH APPLY TO ITS USE.
**
** 1. The Software is owned by the IAU SOFA Board ("SOFA").
**
** 2. Permission is granted to anyone to use the SOFA software for any
** purpose, including commercial applications, free of charge and
** without payment of royalties, subject to the conditions and
** restrictions listed below.
**
** 3. You (the user) may copy and distribute SOFA source code to others,
** and use and adapt its code and algorithms in your own software,
** on a world-wide, royalty-free basis. That portion of your
** distribution that does not consist of intact and unchanged copies
** of SOFA source code files is a "derived work" that must comply
** with the following requirements:
**
** a) Your work shall be marked or carry a statement that it
** (i) uses routines and computations derived by you from
** software provided by SOFA under license to you; and
** (ii) does not itself constitute software provided by and/or
** endorsed by SOFA.
**
** b) The source code of your derived work must contain descriptions
** of how the derived work is based upon, contains and/or differs
** from the original SOFA software.
**
** c) The names of all routines in your derived work shall not
** include the prefix "iau" or "sofa" or trivial modifications
** thereof such as changes of case.
**
** d) The origin of the SOFA components of your derived work must
** not be misrepresented; you must not claim that you wrote the
** original software, nor file a patent application for SOFA
** software or algorithms embedded in the SOFA software.
**
** e) These requirements must be reproduced intact in any source
** distribution and shall apply to anyone to whom you have
** granted a further right to modify the source code of your
** derived work.
**
** Note that, as originally distributed, the SOFA software is
** intended to be a definitive implementation of the IAU standards,
** and consequently third-party modifications are discouraged. All
** variations, no matter how minor, must be explicitly marked as
** such, as explained above.
**
** 4. You shall not cause the SOFA software to be brought into
** disrepute, either by misuse, or use for inappropriate tasks, or
** by inappropriate modification.
**
** 5. The SOFA software is provided "as is" and SOFA makes no warranty
** as to its use or performance. SOFA does not and cannot warrant
** the performance or results which the user may obtain by using the
** SOFA software. SOFA makes no warranties, express or implied, as
** to non-infringement of third party rights, merchantability, or
** fitness for any particular purpose. In no event will SOFA be
** liable to the user for any consequential, incidental, or special
** damages, including any lost profits or lost savings, even if a
** SOFA representative has been advised of such damages, or for any
** claim by any third party.
**
** 6. The provision of any version of the SOFA software under the terms
** and conditions specified herein does not imply that future
** versions will also be made available under the same terms and
** conditions.
*
** In any published work or commercial product which uses the SOFA
** software directly, acknowledgement (see www.iausofa.org) is
** appreciated.
**
** Correspondence concerning SOFA software should be addressed as
** follows:
**
** By email: sofa@ukho.gov.uk
** By post: IAU SOFA Center
** HM Nautical Almanac Office
** UK Hydrographic Office
** Admiralty Way, Taunton
** Somerset, TA1 2DN
** United Kingdom
**
**--------------------------------------------------------------------*/
}