int iauPvstar(double pv[2][3], double *ra, double *dec,
double *pmr, double *pmd, double *px, double *rv)
/*
** - - - - - - - - - -
** i a u P v s t a r
** - - - - - - - - - -
**
** Convert star position+velocity vector to catalog coordinates.
**
** This function is part of the International Astronomical Union's
** SOFA (Standards Of Fundamental Astronomy) software collection.
**
** Status: support function.
**
** 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 iauStarpv), 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 iauStarpv.
**
** Called:
** iauPn decompose p-vector into modulus and direction
** iauPdp scalar product of two p-vectors
** iauSxp multiply p-vector by scalar
** iauPmp p-vector minus p-vector
** iauPm modulus of p-vector
** iauPpp p-vector plus p-vector
** iauPv2s pv-vector to spherical
** iauAnp normalize angle into range 0 to 2pi
**
** Reference:
**
** Stumpff, P., 1985, Astron.Astrophys. 144, 232-240.
**
** This revision: 2013 June 18
**
** SOFA release 2015-02-09
**
** Copyright (C) 2015 IAU SOFA Board. See notes at end.
*/
{
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). */
iauPn(pv[0], &r, x);
vr = iauPdp(x, pv[1]);
iauSxp(vr, x, ur);
/* Isolate the transverse component of the velocity (AU/day, inertial). */
iauPmp(pv[1], ur, ut);
vt = iauPm(ut);
/* Special-relativity dimensionless parameters. */
bett = vt / DC;
betr = vr / 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;
iauSxp(w, ur, usr);
/* Apply relativistic correction factor to tangential velocity */
/* component. */
iauSxp(1.0/d, ut, ust);
/* Combine the two to obtain the observed velocity vector (AU/day). */
iauPpp(usr, ust, pv[1]);
/* Cartesian to spherical. */
iauPv2s(pv, &a, dec, &r, &rad, &decd, &rd);
if (r == 0.0) return -2;
/* Return RA in range 0 to 2pi. */
*ra = iauAnp(a);
/* Return proper motions in radians per year. */
*pmr = rad * DJY;
*pmd = decd * DJY;
/* Return parallax in arcsec. */
*px = DR2AS / r;
/* Return radial velocity in km/s. */
*rv = 1e-3 * rd * DAU / DAYSEC;
/* OK status. */
return 0;
/*----------------------------------------------------------------------
**
** Copyright (C) 2015
** 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: [email protected]
** By post: IAU SOFA Center
** HM Nautical Almanac Office
** UK Hydrographic Office
** Admiralty Way, Taunton
** Somerset, TA1 2DN
** United Kingdom
**
**--------------------------------------------------------------------*/
}
int iauStarpv(double ra, double dec,
double pmr, double pmd, double px, double rv,
double pv[2][3])
/*
** - - - - - - - - - -
** i a u S t a r p v
** - - - - - - - - - -
**
** Convert star catalog coordinates to position+velocity vector.
**
** Status: support function.
**
** Given (Note 1):
** 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 (arcseconds)
** rv double radial velocity (km/s, positive = receding)
**
** Returned (Note 2):
** pv double[2][3] pv-vector (AU, AU/day)
**
** Returned (function value):
** int status:
** 0 = no warnings
** 1 = distance overridden (Note 6)
** 2 = excessive speed (Note 7)
** 4 = solution didn't converge (Note 8)
** else = binary logical OR of the above
**
** Notes:
**
** 1) The star data accepted 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 pv-vector is likely to be
** merely an intermediate result, so that a change of time unit
** would 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.
**
** 2) The resulting position and velocity pv-vector is with respect to
** the same frame and, like the catalog coordinates, is freed from
** the effects of secular aberration. Should the "coordinate
** direction", where the object was located at the catalog epoch, be
** required, it may be obtained by calculating the magnitude of the
** position vector pv[0][0-2] dividing by the speed of light in
** AU/day to give the light-time, and then multiplying the space
** velocity pv[1][0-2] by this light-time and adding the result to
** pv[0][0-2].
**
** Summarizing, the pv-vector returned is for most stars almost
** identical to the result of applying the standard geometrical
** "space motion" transformation. The differences, which are the
** subject of the Stumpff paper referenced 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 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 interpreted
** to mean that the object is on the "celestial sphere", the radius
** of which is an arbitrary (large) value (see the constant PXMIN).
** When the distance is overridden in this way, the status,
** initially zero, has 1 added to it.
**
** 7) If the space velocity is a significant fraction of c (see the
** constant VMAX), it is arbitrarily set to zero. When this action
** occurs, 2 is added to the status.
**
** 8) The relativistic adjustment involves an iterative calculation.
** If the process fails to converge within a set number (IMAX) of
** iterations, 4 is added to the status.
**
** 9) The inverse transformation is performed by the function
** iauPvstar.
**
** Called:
** iauS2pv spherical coordinates to pv-vector
** iauPm modulus of p-vector
** iauZp zero p-vector
** iauPn decompose p-vector into modulus and direction
** iauPdp scalar product of two p-vectors
** iauSxp multiply p-vector by scalar
** iauPmp p-vector minus p-vector
** iauPpp p-vector plus p-vector
**
** Reference:
**
** Stumpff, P., 1985, Astron.Astrophys. 144, 232-240.
**
** This revision: 2009 July 6
**
** Original version 2012-03-01
**
** Copyright (C) 2013 Naoki Arita. See notes at end.
*/
{
/* Smallest allowed parallax */
static const double PXMIN = 1e-7;
/* Largest allowed speed (fraction of c) */
static const double VMAX = 0.5;
/* Maximum number of iterations for relativistic solution */
static const int IMAX = 100;
int i, iwarn;
double w, r, rd, rad, decd, v, x[3], usr[3], ust[3],
vsr, vst, betst, betsr, bett, betr,
dd, ddel, ur[3], ut[3],
d = 0.0, del = 0.0, /* to prevent */
odd = 0.0, oddel = 0.0, /* compiler */
od = 0.0, odel = 0.0; /* warnings */
/* Distance (AU). */
if (px >= PXMIN) {
w = px;
iwarn = 0;
} else {
w = PXMIN;
iwarn = 1;
}
r = DR2AS / w;
/* Radial velocity (AU/day). */
rd = DAYSEC * rv * 1e3 / DAU;
/* Proper motion (radian/day). */
rad = pmr / DJY;
decd = pmd / DJY;
/* To pv-vector (AU,AU/day). */
iauS2pv(ra, dec, r, rad, decd, rd, pv);
/* If excessive velocity, arbitrarily set it to zero. */
v = iauPm(pv[1]);
if (v / DC > VMAX) {
iauZp(pv[1]);
iwarn += 2;
}
/* Isolate the radial component of the velocity (AU/day). */
iauPn(pv[0], &w, x);
vsr = iauPdp(x, pv[1]);
iauSxp(vsr, x, usr);
/* Isolate the transverse component of the velocity (AU/day). */
iauPmp(pv[1], usr, ust);
vst = iauPm(ust);
/* Special-relativity dimensionless parameters. */
betsr = vsr / DC;
betst = vst / DC;
/* Determine the inertial-to-observed relativistic correction terms. */
bett = betst;
betr = betsr;
for (i = 0; i < IMAX; i++) {
d = 1.0 + betr;
del = sqrt(1.0 - betr*betr - bett*bett) - 1.0;
betr = d * betsr + del;
bett = d * betst;
if (i > 0) {
dd = fabs(d - od);
ddel = fabs(del - odel);
if ((i > 1) && (dd >= odd) && (ddel >= oddel)) break;
odd = dd;
oddel = ddel;
}
od = d;
odel = del;
}
if (i >= IMAX) iwarn += 4;
/* Replace observed radial velocity with inertial value. */
w = (betsr != 0.0) ? d + del / betsr : 1.0;
iauSxp(w, usr, ur);
/* Replace observed tangential velocity with inertial value. */
iauSxp(d, ust, ut);
/* Combine the two to obtain the inertial space velocity. */
iauPpp(ur, ut, pv[1]);
/* Return the status. */
return iwarn;
/*----------------------------------------------------------------------
**
** Celes is a wrapper of the SOFA Library for Ruby.
**
** This file is redistributed and relicensed in accordance with
** the SOFA Software License (http://www.iausofa.org/tandc.html).
**
** The original library is available from IAU Standards of
** Fundamental Astronomy (http://www.iausofa.org/).
**
**
**
**
**
** Copyright (C) 2013, Naoki Arita
** All rights reserved.
**
** 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.
**
**--------------------------------------------------------------------*/
}
void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[]) {
size_t numRow,numVec;
mxArray *retMat;
double *xVec, *retData;
double TT1, TT2, UT11, UT12;
//The if-statements below should properly initialize all of the EOP.
//The following initializations to zero are to suppress warnings when
//compiling with -Wconditional-uninitialized.
double dX=0;
double dY=0;
double deltaT=0;
double LOD=0;
double GCRS2TIRS[3][3];
//Polar motion matrix. ITRS=POM*TIRS. We will just be setting it to the
//identity matrix as polar motion is not taken into account when going
//to the TIRS.
double rident[3][3]={{1,0,0},{0,1,0},{0,0,1}};
double Omega[3];//The rotation vector in the TIRS
if(nrhs<3||nrhs>6){
mexErrMsgTxt("Wrong number of inputs");
}
if(nlhs>2) {
mexErrMsgTxt("Wrong number of outputs.");
}
checkRealDoubleArray(prhs[0]);
numRow = mxGetM(prhs[0]);
numVec = mxGetN(prhs[0]);
if(!(numRow==3||numRow==6)) {
mexErrMsgTxt("The input vector has a bad dimensionality.");
}
xVec=(double*)mxGetData(prhs[0]);
TT1=getDoubleFromMatlab(prhs[1]);
TT2=getDoubleFromMatlab(prhs[2]);
//If some values from the function getEOP will be needed
if(nrhs<=5||mxIsEmpty(prhs[3])||mxIsEmpty(prhs[4])||mxIsEmpty(prhs[5])) {
mxArray *retVals[5];
double *dXdY;
mxArray *JulUTCMATLAB[2];
double JulUTC[2];
int retVal;
//Get the time in UTC to look up the parameters by going to TAI and
//then UTC.
retVal=iauTttai(TT1, TT2, &JulUTC[0], &JulUTC[1]);
if(retVal!=0) {
mexErrMsgTxt("An error occurred computing TAI.");
}
retVal=iauTaiutc(JulUTC[0], JulUTC[1], &JulUTC[0], &JulUTC[1]);
switch(retVal){
case 1:
mexWarnMsgTxt("Dubious Date entered.");
break;
case -1:
mexErrMsgTxt("Unacceptable date entered");
break;
default:
break;
}
JulUTCMATLAB[0]=doubleMat2Matlab(&JulUTC[0],1,1);
JulUTCMATLAB[1]=doubleMat2Matlab(&JulUTC[1],1,1);
//Get the Earth orientation parameters for the given date.
mexCallMATLAB(5,retVals,2,JulUTCMATLAB,"getEOP");
mxDestroyArray(JulUTCMATLAB[0]);
mxDestroyArray(JulUTCMATLAB[1]);
//%We do not need the polar motion coordinates.
mxDestroyArray(retVals[0]);
checkRealDoubleArray(retVals[1]);
if(mxGetM(retVals[1])!=2||mxGetN(retVals[1])!=1) {
mxDestroyArray(retVals[1]);
mxDestroyArray(retVals[2]);
mxDestroyArray(retVals[3]);
mxDestroyArray(retVals[4]);
mexErrMsgTxt("Error using the getEOP function.");
return;
}
dXdY=(double*)mxGetData(retVals[1]);
dX=dXdY[0];
dY=dXdY[1];
//This is TT-UT1
deltaT=getDoubleFromMatlab(retVals[3]);
LOD=getDoubleFromMatlab(retVals[4]);
//Free the returned arrays.
mxDestroyArray(retVals[1]);
mxDestroyArray(retVals[2]);
mxDestroyArray(retVals[3]);
mxDestroyArray(retVals[4]);
}
//If deltaT=TT-UT1 is given
if(nrhs>3&&!mxIsEmpty(prhs[3])) {
deltaT=getDoubleFromMatlab(prhs[3]);
}
//Obtain UT1 from terestrial time and deltaT.
iauTtut1(TT1, TT2, deltaT, &UT11, &UT12);
//Get celestial pole offsets, if given.
if(nrhs>4&&!mxIsEmpty(prhs[4])) {
size_t dim1, dim2;
checkRealDoubleArray(prhs[4]);
dim1 = mxGetM(prhs[4]);
dim2 = mxGetN(prhs[4]);
if((dim1==2&&dim2==1)||(dim1==1&&dim2==2)) {
double *dXdY=(double*)mxGetData(prhs[4]);
dX=dXdY[0];
dY=dXdY[1];
} else {
mexErrMsgTxt("The celestial pole offsets have the wrong dimensionality.");
return;
}
}
//If LOD is given
if(nrhs>5&&mxIsEmpty(prhs[5])) {
LOD=getDoubleFromMatlab(prhs[5]);
}
//Compute the rotation matrix for going from GCRS to ITRS as well as
//the instantaneous vector angular momentum due to the Earth's rotation
//in TIRS coordinates.
{
double x, y, s, era;
double rc2i[3][3];
double omega;
//Get the X,Y coordinates of the Celestial Intermediate Pole (CIP) and
//the Celestial Intermediate Origin (CIO) locator s, using the IAU 2006
//precession and IAU 2000A nutation models.
iauXys06a(TT1, TT2, &x, &y, &s);
//Add the CIP offsets.
x += dX;
y += dY;
//Get the GCRS-to-CIRS matrix
iauC2ixys(x, y, s, rc2i);
//Find the Earth rotation angle for the given UT1 time.
era = iauEra00(UT11, UT12);
//Set the polar motion matrix to the identity matrix so that the
//conversion stops at the TIRS instead of the ITRS.
//Combine the GCRS-to-CIRS matrix, the Earth rotation angle, and use
//the identity matrix instead of the polar motion matrix to get a
//to get the rotation matrix to go from GCRS to TIRS.
iauC2tcio(rc2i, era, rident,GCRS2TIRS);
//Next, to be able to transform the velocity, the rotation of the Earth
//has to be taken into account.
//The angular velocity vector of the Earth in the TIRS in radians.
omega=getScalarMatlabClassConst("Constants","IERSMeanEarthRotationRate");
//Adjust for LOD
omega=omega*(1-LOD/86400.0);//86400.0 is the number of seconds in a TT
//day.
Omega[0]=0;
Omega[1]=0;
Omega[2]=omega;
}
//Allocate space for the return vectors.
retMat=mxCreateDoubleMatrix(numRow,numVec,mxREAL);
retData=(double*)mxGetData(retMat);
{
size_t curVec;
for(curVec=0;curVec<numVec;curVec++) {
//Multiply the position vector with the rotation matrix.
iauRxp(GCRS2TIRS, xVec+numRow*curVec, retData+numRow*curVec);
//If a velocity vector was given.
if(numRow>3) {
double *posGCRS=xVec+numRow*curVec;
double posTIRS[3];
double *velGCRS=xVec+numRow*curVec+3;//Velocity in GCRS
double velTIRS[3];
double *retDataVel=retData+numRow*curVec+3;
double rotVel[3];
//If a velocity was provided with the position, first
//convert to TIRS coordinates, then account for the
//rotation of the Earth.
//Convert velocity from GCRS to TIRS.
iauRxp(GCRS2TIRS, velGCRS, velTIRS);
//Convert position from GCRS to TIRS
iauRxp(GCRS2TIRS, posGCRS, posTIRS);
//Evaluate the cross product for the angular velocity due
//to the Earth's rotation.
iauPxp(Omega, posTIRS, rotVel);
//Subtract out the instantaneous velocity due to rotation.
iauPmp(velTIRS, rotVel, retDataVel);
}
}
}
plhs[0]=retMat;
//If the rotation matrix is desired on the output.
if(nlhs>1) {
double *elPtr;
size_t i,j;
plhs[1]=mxCreateDoubleMatrix(3,3,mxREAL);
elPtr=(double*)mxGetData(plhs[1]);
for (i=0;i<3;i++) {
for(j=0;j<3;j++) {
elPtr[i+3*j]=GCRS2TIRS[i][j];
}
}
}
}
void iauPvmpv(double a[2][3], double b[2][3], double amb[2][3])
/*
** - - - - - - - - -
** i a u P v m p v
** - - - - - - - - -
**
** Subtract one pv-vector from another.
**
** This function is part of the International Astronomical Union's
** SOFA (Standards Of Fundamental Astronomy) software collection.
**
** Status: vector/matrix support function.
**
** Given:
** a double[2][3] first pv-vector
** b double[2][3] second pv-vector
**
** Returned:
** amb double[2][3] a - b
**
** Note:
** It is permissible to re-use the same array for any of the
** arguments.
**
** Called:
** iauPmp p-vector minus p-vector
**
** This revision: 2013 June 18
**
** SOFA release 2016-05-03
**
** Copyright (C) 2016 IAU SOFA Board. See notes at end.
*/
{
iauPmp(a[0], b[0], amb[0]);
iauPmp(a[1], b[1], amb[1]);
return;
/*----------------------------------------------------------------------
**
** Copyright (C) 2016
** 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: [email protected]
** By post: IAU SOFA Center
** HM Nautical Almanac Office
** UK Hydrographic Office
** Admiralty Way, Taunton
** Somerset, TA1 2DN
** United Kingdom
**
**--------------------------------------------------------------------*/
}
double iauPap(double a[3], double b[3])
/*
** - - - - - - -
** i a u P a p
** - - - - - - -
**
** Position-angle from two p-vectors.
**
** This function is part of the International Astronomical Union's
** SOFA (Standards Of Fundamental Astronomy) software collection.
**
** Status: vector/matrix support function.
**
** Given:
** a double[3] direction of reference point
** b double[3] direction of point whose PA is required
**
** Returned (function value):
** double position angle of b with respect to a (radians)
**
** Notes:
**
** 1) The result is the position angle, in radians, of direction b with
** respect to direction a. It is in the range -pi to +pi. The
** sense is such that if b is a small distance "north" of a the
** position angle is approximately zero, and if b is a small
** distance "east" of a the position angle is approximately +pi/2.
**
** 2) The vectors a and b need not be of unit length.
**
** 3) Zero is returned if the two directions are the same or if either
** vector is null.
**
** 4) If vector a is at a pole, the result is ill-defined.
**
** Called:
** iauPn decompose p-vector into modulus and direction
** iauPm modulus of p-vector
** iauPxp vector product of two p-vectors
** iauPmp p-vector minus p-vector
** iauPdp scalar product of two p-vectors
**
** This revision: 2008 May 25
**
** SOFA release 2012-03-01
**
** Copyright (C) 2012 IAU SOFA Board. See notes at end.
*/
{
double am, au[3], bm, st, ct, xa, ya, za, eta[3], xi[3], a2b[3], pa;
/* Modulus and direction of the a vector. */
iauPn(a, &am, au);
/* Modulus of the b vector. */
bm = iauPm(b);
/* Deal with the case of a null vector. */
if ((am == 0.0) || (bm == 0.0)) {
st = 0.0;
ct = 1.0;
} else {
/* The "north" axis tangential from a (arbitrary length). */
xa = a[0];
ya = a[1];
za = a[2];
eta[0] = -xa * za;
eta[1] = -ya * za;
eta[2] = xa*xa + ya*ya;
/* The "east" axis tangential from a (same length). */
iauPxp(eta, au, xi);
/* The vector from a to b. */
iauPmp(b, a, a2b);
/* Resolve into components along the north and east axes. */
st = iauPdp(a2b, xi);
ct = iauPdp(a2b, eta);
/* Deal with degenerate cases. */
if ((st == 0.0) && (ct == 0.0)) ct = 1.0;
}
/* Position angle. */
pa = atan2(st, ct);
return pa;
/*----------------------------------------------------------------------
**
** Copyright (C) 2012
** 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: [email protected]
** By post: IAU SOFA Center
** HM Nautical Almanac Office
** UK Hydrographic Office
** Admiralty Way, Taunton
** Somerset, TA1 2DN
** United Kingdom
**
**--------------------------------------------------------------------*/
}
void iauLdn(int n, iauLDBODY b[], double ob[3], double sc[3],
double sn[3])
/*+
** - - - - - - -
** i a u L d n
** - - - - - - -
**
** For a star, apply light deflection by multiple solar-system bodies,
** as part of transforming coordinate direction into natural direction.
**
** This function is part of the International Astronomical Union's
** SOFA (Standards of Fundamental Astronomy) software collection.
**
** Status: support function.
**
** Given:
** n int number of bodies (note 1)
** b iauLDBODY[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 iauLd function. Similarly, iauLd 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:
** iauCp copy p-vector
** iauPdp scalar product of two p-vectors
** iauPmp p-vector minus p-vector
** iauPpsp p-vector plus scaled p-vector
** iauPn decompose p-vector into modulus and direction
** iauLd light deflection by a solar-system body
**
** This revision: 2017 March 16
**
** SOFA release 2017-04-20
**
** Copyright (C) 2017 IAU SOFA Board. See notes at end.
*/
{
/* Light time for 1 au (days) */
const double CR = AULT/DAYSEC;
int i;
double v[3], dt, ev[3], em, e[3];
/* Star direction prior to deflection. */
iauCp(sc, sn);
/* Body by body. */
for ( i = 0; i < n; i++ ) {
/* Body to observer vector at epoch of observation (au). */
iauPmp ( ob, b[i].pv[0], v );
/* Minus the time since the light passed the body (days). */
dt = iauPdp(sn,v) * CR;
/* Neutralize if the star is "behind" the observer. */
dt = gmin(dt, 0.0);
/* Backtrack the body to the time the light was passing the body. */
iauPpsp(v, -dt, b[i].pv[1], ev);
/* Body to observer vector as magnitude and direction. */
iauPn(ev, &em, e);
/* Apply light deflection for this body. */
iauLd ( b[i].bm, sn, sn, e, em, b[i].dl, sn );
/* Next body. */
}
/* Finished. */
/*----------------------------------------------------------------------
**
** Copyright (C) 2017
** 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: [email protected]
** By post: IAU SOFA Center
** HM Nautical Almanac Office
** UK Hydrographic Office
** Admiralty Way, Taunton
** Somerset, TA1 2DN
** United Kingdom
**
**--------------------------------------------------------------------*/
}
void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[]) {
size_t numRow,numVec;
mxArray *retMat;
double *xVec, *retData;
double TT1, TT2, UT11, UT12;
//The if-statements below should properly initialize all of the EOP.
//The following initializations to zero are to suppress warnings when
//compiling with -Wconditional-uninitialized.
double xp=0;
double yp=0;
double deltaT=0;
double LOD=0;
double TEME2ITRS[3][3];
double TEME2PEF[3][3];
double W[3][3];//Polar motion to go from PEF to ITRS.
double Omega[3];//The angular velocity vector for the Earth's rotation.
if(nrhs<3||nrhs>6){
mexErrMsgTxt("Wrong number of inputs");
}
if(nlhs>2) {
mexErrMsgTxt("Wrong number of outputs.");
return;
}
checkRealDoubleArray(prhs[0]);
numRow = mxGetM(prhs[0]);
numVec = mxGetN(prhs[0]);
if(!(numRow==3||numRow==6)) {
mexErrMsgTxt("The input vector has a bad dimensionality.");
}
xVec=(double*)mxGetData(prhs[0]);
TT1=getDoubleFromMatlab(prhs[1]);
TT2=getDoubleFromMatlab(prhs[2]);
//If some values from the function getEOP will be needed
if(nrhs<6||mxGetM(prhs[3])==0||mxGetM(prhs[4])==0||mxGetM(prhs[5])==0) {
mxArray *retVals[5];
double *xpyp;
mxArray *JulUTCMATLAB[2];
double JulUTC[2];
int retVal;
//Get the time in UTC to look up the parameters by going to TAI and
//then UTC.
retVal=iauTttai(TT1, TT2, &JulUTC[0], &JulUTC[1]);
if(retVal!=0) {
mexErrMsgTxt("An error occurred computing TAI.");
}
retVal=iauTaiutc(JulUTC[0], JulUTC[1], &JulUTC[0], &JulUTC[1]);
switch(retVal){
case 1:
mexWarnMsgTxt("Dubious Date entered.");
break;
case -1:
mexErrMsgTxt("Unacceptable date entered");
break;
default:
break;
}
JulUTCMATLAB[0]=doubleMat2Matlab(&JulUTC[0],1,1);
JulUTCMATLAB[1]=doubleMat2Matlab(&JulUTC[1],1,1);
//Get the Earth orientation parameters for the given date.
mexCallMATLAB(5,retVals,2,JulUTCMATLAB,"getEOP");
mxDestroyArray(JulUTCMATLAB[0]);
mxDestroyArray(JulUTCMATLAB[1]);
checkRealDoubleArray(retVals[0]);
checkRealDoubleArray(retVals[1]);
if(mxGetM(retVals[0])!=2||mxGetN(retVals[0])!=1||mxGetM(retVals[1])!=2||mxGetN(retVals[1])!=1) {
mxDestroyArray(retVals[0]);
mxDestroyArray(retVals[1]);
mxDestroyArray(retVals[2]);
mxDestroyArray(retVals[3]);
mxDestroyArray(retVals[4]);
mexErrMsgTxt("Error using the getEOP function.");
return;
}
xpyp=(double*)mxGetData(retVals[0]);
xp=xpyp[0];
yp=xpyp[1];
//The celestial pole offsets are not used.
//This is TT-UT1
deltaT=getDoubleFromMatlab(retVals[3]);
LOD=getDoubleFromMatlab(retVals[4]);
//Free the returned arrays.
mxDestroyArray(retVals[0]);
mxDestroyArray(retVals[1]);
mxDestroyArray(retVals[2]);
mxDestroyArray(retVals[3]);
mxDestroyArray(retVals[4]);
}
//If deltaT=TT-UT1 is given
if(nrhs>3&&mxGetM(prhs[3])!=0) {
deltaT=getDoubleFromMatlab(prhs[3]);
}
//Obtain UT1 from terestrial time and deltaT.
iauTtut1(TT1, TT2, deltaT, &UT11, &UT12);
//Get polar motion values, if given.
if(nrhs>4&&mxGetM(prhs[4])!=0) {
size_t dim1, dim2;
checkRealDoubleArray(prhs[4]);
dim1 = mxGetM(prhs[4]);
dim2 = mxGetN(prhs[4]);
if((dim1==2&&dim2==1)||(dim1==1&&dim2==2)) {
double *xpyp=(double*)mxGetData(prhs[4]);
xp=xpyp[0];
yp=xpyp[1];
} else {
mexErrMsgTxt("The celestial pole offsets have the wrong dimensionality.");
return;
}
}
//If LOD is given
if(nrhs>5&&mxGetM(prhs[5])!=0) {
LOD=getDoubleFromMatlab(prhs[5]);
}
{
double GMST1982=iauGmst82(UT11, UT12);
double omega;
//Get Greenwhich mean sidereal time under the IAU's 1982 model. This
//is given in radians and will be used to build a rotation matrix to
//rotate into the PEF system.
GMST1982=iauGmst82(UT11, UT12);
{
double cosGMST,sinGMST;
cosGMST=cos(GMST1982);
sinGMST=sin(GMST1982);
//Build the rotation matrix to rotate by GMST about the z-axis. This
//will put the position vector in the PEF system.
TEME2PEF[0][0]=cosGMST;
TEME2PEF[0][1]=sinGMST;
TEME2PEF[0][2]=0;
TEME2PEF[1][0]=-sinGMST;
TEME2PEF[1][1]=cosGMST;
TEME2PEF[1][2]=0;
TEME2PEF[2][0]=0;
TEME2PEF[2][1]=0;
TEME2PEF[2][2]=1.0;
}
//To go from PEF to ITRS, we need to build the polar motion matrix
//using the IAU's 1980 conventions.
{
double cosXp,sinXp,cosYp,sinYp;
cosXp=cos(xp);
sinXp=sin(xp);
cosYp=cos(yp);
sinYp=sin(yp);
W[0][0]=cosXp;
W[0][1]=sinXp*sinYp;
W[0][2]=sinXp*cosYp;
W[1][0]=0;
W[1][1]=cosYp;
W[1][2]=-sinYp;
W[2][0]=-sinXp;
W[2][1]=cosXp*sinXp;
W[2][2]=cosXp*cosYp;
}
//The total rotation matrix is thus the product of the two rotations.
//TEME2ITRS=W*TEME2PEF;
iauRxr(W, TEME2PEF, TEME2ITRS);
//The angular velocity vector of the Earth in the TIRS in radians.
omega=getScalarMatlabClassConst("Constants","IERSMeanEarthRotationRate");
//Adjust for LOD
omega=omega*(1-LOD/86400.0);//86400.0 is the number of seconds in a TT day.
Omega[0]=0;
Omega[1]=0;
Omega[2]=omega;
}
//Allocate space for the return vectors.
retMat=mxCreateDoubleMatrix(numRow,numVec,mxREAL);
retData=(double*)mxGetData(retMat);
{
size_t curVec;
for(curVec=0;curVec<numVec;curVec++) {
//Multiply the position vector with the rotation matrix.
iauRxp(TEME2ITRS, xVec+numRow*curVec, retData+numRow*curVec);
//If a velocity vector was given.
if(numRow>3) {
double *posTEME=xVec+numRow*curVec;
double *velTEME=xVec+numRow*curVec+3;//Velocity in TEME
double posPEF[3];
double velPEF[3];
double *retDataVel=retData+numRow*curVec+3;
double rotVel[3];
//If a velocity was provided with the position, first
//convert to PEF coordinates, then account for the rotation of
//the Earth, then rotate into ITRS coordinates.
//Convert velocity from TEME to PEF.
iauRxp(TEME2PEF, velTEME, velPEF);
//Convert position from TEME to PEF
iauRxp(TEME2PEF, posTEME, posPEF);
//Evaluate the cross product for the angular velocity due
//to the Earth's rotation.
iauPxp(Omega, posPEF, rotVel);
//Subtract out the instantaneous velocity due to rotation.
iauPmp(velPEF, rotVel, retDataVel);
//Rotate from the PEF into the ITRS using the polar motion
//matrix.
iauRxp(W, retDataVel, retDataVel);
}
}
}
plhs[0]=retMat;
if(nlhs>1) {
double *elPtr;
size_t i,j;
plhs[1]=mxCreateDoubleMatrix(3,3,mxREAL);
elPtr=(double*)mxGetData(plhs[1]);
for (i=0;i<3;i++) {
for(j=0;j<3;j++) {
elPtr[i+3*j]=TEME2ITRS[i][j];
}
}
}
}
void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[]) {
double TT1,TT2,*xVec;
double deltaT=0;
double LOD=0;
size_t numRow,numVec;
double CIRS2TIRS[3][3];
double Omega[3];//The rotation vector in the TIRS
mxArray *retMat;
double *retData;
if(nrhs<3||nrhs>5){
mexErrMsgTxt("Wrong number of inputs");
}
if(nlhs>2) {
mexErrMsgTxt("Wrong number of outputs.");
}
checkRealDoubleArray(prhs[0]);
numRow = mxGetM(prhs[0]);
numVec = mxGetN(prhs[0]);
if(!(numRow==3||numRow==6)) {
mexErrMsgTxt("The input vector has a bad dimensionality.");
}
xVec=(double*)mxGetData(prhs[0]);
TT1=getDoubleFromMatlab(prhs[1]);
TT2=getDoubleFromMatlab(prhs[2]);
//If some values from the function getEOP will be needed
if(nrhs<=4||mxIsEmpty(prhs[3])||mxIsEmpty(prhs[4])) {
mxArray *retVals[5];
mxArray *JulUTCMATLAB[2];
double JulUTC[2];
int retVal;
//Get the time in UTC to look up the parameters by going to TAI and
//then UTC.
retVal=iauTttai(TT1, TT2, &JulUTC[0], &JulUTC[1]);
if(retVal!=0) {
mexErrMsgTxt("An error occurred computing TAI.");
}
retVal=iauTaiutc(JulUTC[0], JulUTC[1], &JulUTC[0], &JulUTC[1]);
switch(retVal){
case 1:
mexWarnMsgTxt("Dubious Date entered.");
break;
case -1:
mexErrMsgTxt("Unacceptable date entered");
break;
default:
break;
}
JulUTCMATLAB[0]=doubleMat2Matlab(&JulUTC[0],1,1);
JulUTCMATLAB[1]=doubleMat2Matlab(&JulUTC[1],1,1);
//Get the Earth orientation parameters for the given date.
mexCallMATLAB(5,retVals,2,JulUTCMATLAB,"getEOP");
mxDestroyArray(JulUTCMATLAB[0]);
mxDestroyArray(JulUTCMATLAB[1]);
//We do not need the polar motion coordinates.
mxDestroyArray(retVals[0]);
//We do not need the celestial pole offsets.
mxDestroyArray(retVals[1]);
//This is TT-UT1
deltaT=getDoubleFromMatlab(retVals[3]);
LOD=getDoubleFromMatlab(retVals[4]);
//Free the returned arrays.
mxDestroyArray(retVals[2]);
mxDestroyArray(retVals[3]);
mxDestroyArray(retVals[4]);
}
//If deltaT=TT-UT1 is given
if(nrhs>3&&!mxIsEmpty(prhs[3])) {
deltaT=getDoubleFromMatlab(prhs[3]);
}
//If LOD is given
if(nrhs>4&&!mxIsEmpty(prhs[4])) {
LOD=getDoubleFromMatlab(prhs[4]);
}
//Compute the rotation matrix for going from CIRS to TIRS as well as
//the instantaneous vector angular momentum due to the Earth's rotation
//in GCRS coordinates.
{
double UT11, UT12;
double era, omega;
//Obtain UT1 from terestrial time and deltaT.
iauTtut1(TT1, TT2, deltaT, &UT11, &UT12);
//Find the Earth rotation angle for the given UT1 time.
era = iauEra00(UT11, UT12);
//Construct the rotation matrix.
CIRS2TIRS[0][0]=1;
CIRS2TIRS[0][1]=0;
CIRS2TIRS[0][2]=0;
CIRS2TIRS[1][0]=0;
CIRS2TIRS[1][1]=1;
CIRS2TIRS[1][2]=0;
CIRS2TIRS[2][0]=0;
CIRS2TIRS[2][1]=0;
CIRS2TIRS[2][2]=1;
iauRz(era, CIRS2TIRS);
//Next, to be able to transform the velocity, the rotation of the Earth
//has to be taken into account.
//The angular velocity vector of the Earth in the TIRS in radians.
omega=getScalarMatlabClassConst("Constants","IERSMeanEarthRotationRate");
//Adjust for LOD
omega=omega*(1-LOD/86400.0);//86400.0 is the number of seconds in a TT
//day.
Omega[0]=0;
Omega[1]=0;
Omega[2]=omega;
}
//Allocate space for the return vectors.
retMat=mxCreateDoubleMatrix(numRow,numVec,mxREAL);
retData=(double*)mxGetData(retMat);
{
size_t curVec;
for(curVec=0;curVec<numVec;curVec++) {
//Multiply the position vector with the rotation matrix.
iauRxp(CIRS2TIRS, xVec+numRow*curVec, retData+numRow*curVec);
//If a velocity vector was given.
if(numRow>3) {
double *posCIRS=xVec+numRow*curVec;
double posTIRS[3];
double *velCIRS=xVec+numRow*curVec+3;//Velocity in GCRS
double velTIRS[3];
double *retDataVel=retData+numRow*curVec+3;
double rotVel[3];
//If a velocity was provided with the position, first
//convert to TIRS coordinates, then account for the
//rotation of the Earth.
//Convert velocity from CIRS to TIRS.
iauRxp(CIRS2TIRS, velCIRS, velTIRS);
//Convert position from CIRS to TIRS
iauRxp(CIRS2TIRS, posCIRS, posTIRS);
//Evaluate the cross product for the angular velocity due
//to the Earth's rotation.
iauPxp(Omega, posTIRS, rotVel);
//Subtract out the instantaneous velocity due to rotation.
iauPmp(velTIRS, rotVel, retDataVel);
}
}
}
plhs[0]=retMat;
//If the rotation matrix is desired on the output.
if(nlhs>1) {
double *elPtr;
size_t i,j;
plhs[1]=mxCreateDoubleMatrix(3,3,mxREAL);
elPtr=(double*)mxGetData(plhs[1]);
for (i=0;i<3;i++) {
for(j=0;j<3;j++) {
elPtr[i+3*j]=CIRS2TIRS[i][j];
}
}
}
}