/*****************************************************************************
** jpl_pleph(ephem,et,ntar,ncent,rrd,calc_velocity) **
******************************************************************************
** **
** This subroutine reads the jpl planetary ephemeris **
** and gives the position and velocity of the point 'ntarg' **
** with respect to 'ncent'. **
** **
** Calling sequence parameters: **
** **
** et = (double) julian ephemeris date at which interpolation **
** is wanted. **
** **
** ntarg = integer number of 'target' point. **
** **
** ncent = integer number of center point. **
** **
** The numbering convention for 'ntarg' and 'ncent' is: **
** **
** 1 = mercury 8 = neptune **
** 2 = venus 9 = pluto **
** 3 = earth 10 = moon **
** 4 = mars 11 = sun **
** 5 = jupiter 12 = solar-system barycenter **
** 6 = saturn 13 = earth-moon barycenter **
** 7 = uranus 14 = nutations (longitude and obliq) **
** 15 = librations, if on eph. file **
** 16 = lunar mantle omega_x,omega_y,omega_z**
** 17 = TT-TDB, if on eph. file **
** **
** (If nutations are wanted, set ntarg = 14. **
** For librations, set ntarg = 15. set ncent= 0. **
** For TT-TDB, set ntarg = 17. I've not actually **
** seen an ntarg = 16 case yet.) **
** **
** rrd = output 6-element, double array of position and velocity **
** of point 'ntarg' relative to 'ncent'. The units are au and **
** au/day. For librations the units are radians and radians **
** per day. In the case of nutations the first four words of **
** rrd will be set to nutations and rates, having units of **
** radians and radians/day. **
** **
** The option is available to have the units in km and km/sec. **
** for this, set km=TRUE at the beginning of the program. **
** **
** calc_velocity = integer flag; if nonzero, velocities will be **
** computed, otherwise not. **
** **
*****************************************************************************/
int DLL_FUNC jpl_pleph(void *ephem, const double et, const int ntarg,
const int ncent, double rrd[], const int calc_velocity)
{
struct jpl_eph_data *eph = (struct jpl_eph_data *)ephem;
double pv[13][6];/* pv is the position/velocity array
NUMBERED FROM ZERO: 0=Mercury,1=Venus,...
8=Pluto,9=Moon,10=Sun,11=SSBary,12=EMBary
First 10 elements (0-9) are affected by
jpl_state(), all are adjusted here. */
int rval = 0;
const int list_val = (calc_velocity ? 2 : 1);
unsigned i;
int list[14]; /* list is a vector denoting, for which "body"
ephemeris values should be calculated by
jpl_state(): 0=Mercury,1=Venus,2=EMBary,...,
8=Pluto, 9=geocentric Moon, 10=nutations in
long. & obliq. 11= lunar librations;
12 = TT-TDB, 13=lunar mantle omegas */
for(i = 0; i < 6; ++i) rrd[i] = 0.0;
if(ntarg == ncent) return(0);
for(i = 0; i < sizeof(list) / sizeof(list[0]); i++)
list[i] = 0;
/* Because of the whacko indexing in JPL ephemerides, we need */
/* to work out way through the following indexing schemes : */
/* ntarg ipt list */
/* 14 11 10 Nutations */
/* 15 12 11 Librations */
/* 16 13 12 Lunar mantle angular vel */
/* 17 14 13 TT - TDB */
for(i = 0; i < 4; i++)
if(ntarg == (int)i + 14)
{
if(eph->ipt[i + 11][1] > 0) /* quantity is in ephemeris */
{
list[i + 10] = list_val;
rval = jpl_state(ephem, et, list, pv, rrd, 0);
}
else /* quantity doesn't exist in the ephemeris file */
rval = JPL_EPH_QUANTITY_NOT_IN_EPHEMERIS;
return(rval);
}
if(ntarg > 13 || ncent > 13 || ntarg < 1 || ncent < 1)
return(JPL_EPH_INVALID_INDEX);
/* force barycentric output by 'state' */
/* set up proper entries in 'list' array for state call */
for(i = 0; i < 2; i++) /* list[] IS NUMBERED FROM ZERO ! */
{
const unsigned k = (i ? ncent : ntarg) - 1;
if(k <= 9) list[k] = list_val; /* Major planets */
if(k == 9) list[2] = list_val; /* for moon, earth state is needed */
if(k == 2) list[9] = list_val; /* for earth, moon state is needed */
if(k == 12) list[2] = list_val; /* EMBary state additionally */
}
/* make call to state */
rval = jpl_state(eph, et, list, pv, rrd, 1);
/* Solar System barycentric Sun state goes to pv[10][] */
if(ntarg == 11 || ncent == 11)
for(i = 0; i < 6; i++)
pv[10][i] = eph->pvsun[i];
/* Solar System Barycenter coordinates & velocities equal to zero */
if(ntarg == 12 || ncent == 12)
for(i = 0; i < 6; i++)
pv[11][i] = 0.0;
/* Solar System barycentric EMBary state: */
if(ntarg == 13 || ncent == 13)
for(i = 0; i < 6; i++)
pv[12][i] = pv[2][i];
/* if moon from earth or earth from moon ..... */
if((ntarg*ncent) == 30 && (ntarg+ncent) == 13)
for(i = 0; i < 6; ++i) pv[2][i]=0.0;
else
{
if(list[2]) /* calculate earth state from EMBary */
for(i = 0; i < list[2] * 3u; ++i)
pv[2][i] -= pv[9][i]/(1.0+eph->emrat);
if(list[9]) /* calculate Solar System barycentric moon state */
for(i = 0; i < list[9] * 3u; ++i)
pv[9][i] += pv[2][i];
}
for(i = 0; i < list_val * 3u; ++i)
rrd[i] = pv[ntarg-1][i] - pv[ncent-1][i];
return(rval);
}
/*****************************************************************************
** jpl_pleph( ephem,et,ntar,ncent,rrd,calc_velocity) **
******************************************************************************
** **
** This subroutine reads the jpl planetary ephemeris **
** and gives the position and velocity of the point 'ntarg' **
** with respect to 'ncent'. **
** **
** Calling sequence parameters: **
** **
** et = (double) julian ephemeris date at which interpolation **
** is wanted. **
** **
** ntarg = integer number of 'target' point. **
** **
** ncent = integer number of center point. **
** **
** The numbering convention for 'ntarg' and 'ncent' is: **
** **
** 1 = mercury 8 = neptune **
** 2 = venus 9 = pluto **
** 3 = earth 10 = moon **
** 4 = mars 11 = sun **
** 5 = jupiter 12 = solar-system barycenter **
** 6 = saturn 13 = earth-moon barycenter **
** 7 = uranus 14 = nutations (longitude and obliq) **
** 15 = librations, if on eph. file **
** **
** (If nutations are wanted, set ntarg = 14. **
** For librations, set ntarg = 15. set ncent= 0) **
** **
** rrd = output 6-element, double array of position and velocity **
** of point 'ntarg' relative to 'ncent'. The units are au and **
** au/day. For librations the units are radians and radians **
** per day. In the case of nutations the first four words of **
** rrd will be set to nutations and rates, having units of **
** radians and radians/day. **
** **
** The option is available to have the units in km and km/sec. **
** for this, set km=TRUE at the begining of the program. **
** **
** calc_velocity = integer flag; if nonzero, velocities will be **
** computed, otherwise not. **
** **
*****************************************************************************/
int DLL_FUNC jpl_pleph( void *ephem, const double et[2], const int ntarg,
const int ncent, double rrd[], const int calc_velocity)
{
struct jpl_eph_data *eph = (struct jpl_eph_data *)ephem;
double pv[13][6];/* pv is the position/velocity array
NUMBERED FROM ZERO: 0=Mercury,1=Venus,...
8=Pluto,9=Moon,10=Sun,11=SSBary,12=EMBary
First 10 elements (0-9) are affected by
jpl_state(), all are adjusted here. */
int rval = 0, list_val = (calc_velocity ? 2 : 1);
int i, k, list[12]; /* list is a vector denoting, for which "body"
ephemeris values should be calculated by
jpl_state(): 0=Mercury,1=Venus,2=EMBary,...,
8=Pluto, 9=geocentric Moon, 10=nutations in
long. & obliq. 11= lunar librations */
for( i = 0; i < 6; ++i) rrd[i] = 0.0;
if( ntarg == ncent) return( 0);
for( i = 0; i < 12; i++) list[i] = 0;
/* check for nutation call */
if( ntarg == 14)
{
if( eph->ipt[11][1] > 0) /* there is nutation on ephemeris */
{
list[10] = list_val;
if( jpl_state( ephem, et, list, pv, rrd, 0))
rval = -1;
}
else /* no nutations on the ephemeris file */
rval = -2;
return( rval);
}
/* check for librations */
if( ntarg == 15)
{
if( eph->ipt[12][1] > 0) /* there are librations on ephemeris file */
{
list[11] = list_val;
if( jpl_state( eph, et, list, pv, rrd, 0))
rval = -3;
for( i = 0; i < 6; ++i)
rrd[i] = pv[10][i]; /* librations */
}
else /* no librations on the ephemeris file */
rval = -4;
return( rval);
}
/* force barycentric output by 'state' */
/* set up proper entries in 'list' array for state call */
for( i = 0; i < 2; i++) /* list[] IS NUMBERED FROM ZERO ! */
{
k = ntarg-1;
if( i == 1) k=ncent-1; /* same for ntarg & ncent */
if( k <= 9) list[k] = list_val; /* Major planets */
if( k == 9) list[2] = list_val; /* for moon, earth state is needed */
if( k == 2) list[9] = list_val; /* for earth, moon state is needed */
if( k == 12) list[2] = list_val; /* EMBary state additionaly */
}
/* make call to state */
if( jpl_state( eph, et, list, pv, rrd, 1))
rval = -5;
/* Solar System barycentric Sun state goes to pv[10][] */
if( ntarg == 11 || ncent == 11)
for( i = 0; i < 6; i++)
pv[10][i] = eph->pvsun[i];
/* Solar System Barycenter coordinates & velocities equal to zero */
if( ntarg == 12 || ncent == 12)
for( i = 0; i < 6; i++)
pv[11][i] = 0.0;
/* Solar System barycentric EMBary state: */
if( ntarg == 13 || ncent == 13)
for( i = 0; i < 6; i++)
pv[12][i] = pv[2][i];
/* if moon from earth or earth from moon ..... */
if( (ntarg*ncent) == 30 && (ntarg+ncent) == 13)
for( i = 0; i < 6; ++i) pv[2][i]=0.0;
else
{
if( list[2]) /* calculate earth state from EMBary */
for( i = 0; i < list[2] * 3; ++i)
pv[2][i] -= pv[9][i]/(1.0+eph->emrat);
if(list[9]) /* calculate Solar System barycentric moon state */
for( i = 0; i < list[9] * 3; ++i)
pv[9][i] += pv[2][i];
}
for( i = 0; i < list_val * 3; ++i)
rrd[i] = pv[ntarg-1][i] - pv[ncent-1][i];
return( rval);
}
