/* Get arbitrary planetary barycenter position. Get the
velocity (in AU/YR) too, if desired. */
void
bodycenter_ssbary(double jd,
double *xyz,
int body,
double *vxyz)
{
double posn[3], vel[3];
static int init=0;
int i;
if (!init) {
if (Initialize_Ephemeris()) exit(1);
init = 1;
}
if (vxyz==NULL) {
Interpolate_Position(jd, body, posn);
} else {
Interpolate_State(jd, body, posn, vel);
}
for (i=0; i<3; i++) {
xyz[i] = posn[i] / R1.AU;
}
if (vxyz!=NULL) /* convert km/s to AU/YR: */
for (i=0; i<3; i++) {
vxyz[i] = vel[i] * (86400. * 365.25) / R1.AU ;
}
return;
}
int dele::init(const char *jpl_name)
{
strcpy(this->fileName, jpl_name);
int res = Initialize_Ephemeris(fileName);
GetParams(H1, H2, R1);
return res;
}
/* Give the Earth geocenter wrt SSBary in AU. */
void
geocenter_ssbary(double jd,
double *xyz)
{
double embary[3],moon[3];
static int init=0;
int i;
if (!init) {
if (Initialize_Ephemeris()) exit(1);
init = 1;
}
Interpolate_Position(jd, EARTH, embary);
Interpolate_Position(jd, MOON, moon);
for (i=0; i<3; i++) {
xyz[i] = (embary[i] - moon[i]/(1.+R1.EMRAT)) / R1.AU;
}
return;
}
