upgrade ast 8.7.1

1 files changed, 216 insertions, 0 deletions

diff --git a/ast/erfa/pvstar.c b/ast/erfa/pvstar.c
new file mode 100644
index 0000000..3a4e00b
--- /dev/null
+++ b/ast/erfa/pvstar.c
@@ -0,0 +1,216 @@
+#include "erfa.h"
+
+int eraPvstar(double pv[2][3], double *ra, double *dec,
+              double *pmr, double *pmd, double *px, double *rv)
+/*
+**  - - - - - - - - - -
+**   e r a P v s t a r
+**  - - - - - - - - - -
+**
+**  Convert star position+velocity vector to catalog coordinates.
+**
+**  Given (Note 1):
+**     pv     double[2][3]   pv-vector (AU, AU/day)
+**
+**  Returned (Note 2):
+**     ra     double         right ascension (radians)
+**     dec    double         declination (radians)
+**     pmr    double         RA proper motion (radians/year)
+**     pmd    double         Dec proper motion (radians/year)
+**     px     double         parallax (arcsec)
+**     rv     double         radial velocity (km/s, positive = receding)
+**
+**  Returned (function value):
+**            int            status:
+**                              0 = OK
+**                             -1 = superluminal speed (Note 5)
+**                             -2 = null position vector
+**
+**  Notes:
+**
+**  1) The specified pv-vector is the coordinate direction (and its rate
+**     of change) for the date at which the light leaving the star
+**     reached the solar-system barycenter.
+**
+**  2) The star data returned by this function are "observables" for an
+**     imaginary observer at the solar-system barycenter.  Proper motion
+**     and radial velocity are, strictly, in terms of barycentric
+**     coordinate time, TCB.  For most practical applications, it is
+**     permissible to neglect the distinction between TCB and ordinary
+**     "proper" time on Earth (TT/TAI).  The result will, as a rule, be
+**     limited by the intrinsic accuracy of the proper-motion and
+**     radial-velocity data;  moreover, the supplied pv-vector is likely
+**     to be merely an intermediate result (for example generated by the
+**     function eraStarpv), so that a change of time unit will cancel
+**     out overall.
+**
+**     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.
+**
+**     Summarizing, the specified pv-vector is for most stars almost
+**     identical to the result of applying the standard geometrical
+**     "space motion" transformation to the catalog data.  The
+**     differences, which are the subject of the Stumpff paper cited
+**     below, are:
+**
+**     (i) In stars with significant radial velocity and proper motion,
+**     the constantly changing light-time distorts the apparent proper
+**     motion.  Note that this is a classical, not a relativistic,
+**     effect.
+**
+**     (ii) The transformation complies with special relativity.
+**
+**  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; the radial velocity is in km/s, but
+**     the pv-vector result is in AU and AU/day.
+**
+**  4) The proper motions are the rate of change of the right ascension
+**     and declination at the catalog epoch and are in radians per Julian
+**     year.  The RA proper motion is in terms of coordinate angle, not
+**     true angle, and will thus be numerically larger at high
+**     declinations.
+**
+**  5) Straight-line motion at constant speed in the inertial frame is
+**     assumed.  If the speed is greater than or equal to the speed of
+**     light, the function aborts with an error status.
+**
+**  6) The inverse transformation is performed by the function eraStarpv.
+**
+**  Called:
+**     eraPn        decompose p-vector into modulus and direction
+**     eraPdp       scalar product of two p-vectors
+**     eraSxp       multiply p-vector by scalar
+**     eraPmp       p-vector minus p-vector
+**     eraPm        modulus of p-vector
+**     eraPpp       p-vector plus p-vector
+**     eraPv2s      pv-vector to spherical
+**     eraAnp       normalize angle into range 0 to 2pi
+**
+**  Reference:
+**
+**     Stumpff, P., 1985, Astron.Astrophys. 144, 232-240.
+**
+**  Copyright (C) 2013-2016, NumFOCUS Foundation.
+**  Derived, with permission, from the SOFA library.  See notes at end of file.
+*/
+{
+   double r, x[3], vr, ur[3], vt, ut[3], bett, betr, d, w, del,
+          usr[3], ust[3], a, rad, decd, rd;
+
+
+/* Isolate the radial component of the velocity (AU/day, inertial). */
+   eraPn(pv[0], &r, x);
+   vr = eraPdp(x, pv[1]);
+   eraSxp(vr, x, ur);
+
+/* Isolate the transverse component of the velocity (AU/day, inertial). */
+   eraPmp(pv[1], ur, ut);
+   vt = eraPm(ut);
+
+/* Special-relativity dimensionless parameters. */
+   bett = vt / ERFA_DC;
+   betr = vr / ERFA_DC;
+
+/* The inertial-to-observed correction terms. */
+   d = 1.0 + betr;
+   w = 1.0 - betr*betr - bett*bett;
+   if (d == 0.0 || w < 0) return -1;
+   del = sqrt(w) - 1.0;
+
+/* Apply relativistic correction factor to radial velocity component. */
+   w = (betr != 0) ? (betr - del) / (betr * d) : 1.0;
+   eraSxp(w, ur, usr);
+
+/* Apply relativistic correction factor to tangential velocity */
+/* component.                                                  */
+   eraSxp(1.0/d, ut, ust);
+
+/* Combine the two to obtain the observed velocity vector (AU/day). */
+   eraPpp(usr, ust, pv[1]);
+
+/* Cartesian to spherical. */
+   eraPv2s(pv, &a, dec, &r, &rad, &decd, &rd);
+   if (r == 0.0) return -2;
+
+/* Return RA in range 0 to 2pi. */
+   *ra = eraAnp(a);
+
+/* Return proper motions in radians per year. */
+   *pmr = rad * ERFA_DJY;
+   *pmd = decd * ERFA_DJY;
+
+/* Return parallax in arcsec. */
+   *px = ERFA_DR2AS / r;
+
+/* Return radial velocity in km/s. */
+   *rv = 1e-3 * rd * ERFA_DAU / ERFA_DAYSEC;
+
+/* 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.
+**  
+*/