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#include "erfa.h"
void eraPvtob(double elong, double phi, double hm,
double xp, double yp, double sp, double theta,
double pv[2][3])
/*
** - - - - - - - - -
** e r a P v t o b
** - - - - - - - - -
**
** Position and velocity of a terrestrial observing station.
**
** Given:
** elong double longitude (radians, east +ve, Note 1)
** phi double latitude (geodetic, radians, Note 1)
** hm double height above ref. ellipsoid (geodetic, m)
** xp,yp double coordinates of the pole (radians, Note 2)
** sp double the TIO locator s' (radians, Note 2)
** theta double Earth rotation angle (radians, Note 3)
**
** Returned:
** pv double[2][3] position/velocity vector (m, m/s, CIRS)
**
** Notes:
**
** 1) The terrestrial coordinates are with respect to the ERFA_WGS84
** reference ellipsoid.
**
** 2) xp and yp are the coordinates (in radians) of the Celestial
** Intermediate Pole with respect to the International Terrestrial
** Reference System (see IERS Conventions), measured along the
** meridians 0 and 90 deg west respectively. sp is the TIO locator
** s', in radians, which positions the Terrestrial Intermediate
** Origin on the equator. For many applications, xp, yp and
** (especially) sp can be set to zero.
**
** 3) If theta is Greenwich apparent sidereal time instead of Earth
** rotation angle, the result is with respect to the true equator
** and equinox of date, i.e. with the x-axis at the equinox rather
** than the celestial intermediate origin.
**
** 4) The velocity units are meters per UT1 second, not per SI second.
** This is unlikely to have any practical consequences in the modern
** era.
**
** 5) No validation is performed on the arguments. Error cases that
** could lead to arithmetic exceptions are trapped by the eraGd2gc
** function, and the result set to zeros.
**
** References:
**
** McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003),
** IERS Technical Note No. 32, BKG (2004)
**
** Urban, S. & Seidelmann, P. K. (eds), Explanatory Supplement to
** the Astronomical Almanac, 3rd ed., University Science Books
** (2013), Section 7.4.3.3.
**
** Called:
** eraGd2gc geodetic to geocentric transformation
** eraPom00 polar motion matrix
** eraTrxp product of transpose of r-matrix and p-vector
**
** Copyright (C) 2013-2016, NumFOCUS Foundation.
** Derived, with permission, from the SOFA library. See notes at end of file.
*/
{
/* Earth rotation rate in radians per UT1 second */
const double OM = 1.00273781191135448 * ERFA_D2PI / ERFA_DAYSEC;
double xyzm[3], rpm[3][3], xyz[3], x, y, z, s, c;
/* Geodetic to geocentric transformation (ERFA_WGS84). */
(void) eraGd2gc(1, elong, phi, hm, xyzm);
/* Polar motion and TIO position. */
eraPom00(xp, yp, sp, rpm);
eraTrxp(rpm, xyzm, xyz);
x = xyz[0];
y = xyz[1];
z = xyz[2];
/* Functions of ERA. */
s = sin(theta);
c = cos(theta);
/* Position. */
pv[0][0] = c*x - s*y;
pv[0][1] = s*x + c*y;
pv[0][2] = z;
/* Velocity. */
pv[1][0] = OM * ( -s*x - c*y );
pv[1][1] = OM * ( c*x - s*y );
pv[1][2] = 0.0;
/* 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.
**
*/
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