def getEarthPosition(jd_tdb):
""" The input time should be on the TDB time scale.
TT - TDB is less than 2 milliseconds.
Returns equatorial rectangular
coordinates in AU referred to the ICRS.
"""
pos, _ = solsys.solarsystem(jd_tdb, 3, 1)
return pos
def make_posn_plots(theta, MJDs, ras, decs, ra_errs, dec_errs, posepoch, psr, filebase=None):
ra, dec, pmra, pmdec, px, Omega, inc = theta
refpos = coords.SkyCoord(ra=ra*u.rad, dec=dec*u.rad, frame='icrs')
modelMJDs = np.linspace(MJDs.min()-20.0, MJDs.max()+20.0, 100)
model_eposns = [solsys.solarsystem(mjd+2400000.5, 3, 0)[0] \
for mjd in modelMJDs]
model_nopsr = [posn_with_pmpx(ra*u.rad, dec*u.rad, pmra, pmdec, px, mjd, posepoch, ep,
dRAother=0.0*u.rad,
dDECother=0.0*u.rad)
for mjd, ep in zip(modelMJDs, model_eposns)]
# Compute the reflex motion from the outer orbit
model_pdRAs, model_pdDECs = psr.reflex_motion(modelMJDs, inc, Omega, 1.0/px)
pdRAs, pdDECs = psr.reflex_motion(baryMJDs, inc, Omega, 1.0/px)
model_psr = [posn_with_pmpx(ra*u.rad, dec*u.rad, pmra, pmdec, px, mjd, posepoch, ep,
dRAother=dra, dDECother=ddec)
for mjd, ep, dra, ddec in \
zip(modelMJDs, model_eposns,
model_pdRAs*u.mas, model_pdDECs*u.mas)]
cosd = np.cos(refpos.dec)
plt.plot(modelMJDs, [((x[0] - refpos.ra)*cosd).to(u.mas).value
for x in model_nopsr], 'k-', label="No reflex motion")
plt.plot(modelMJDs, [((x[0] - refpos.ra)*cosd).to(u.mas).value
for x in model_psr], 'r-', label="With reflex motion")
plt.errorbar(baryMJDs, ((ras - refpos.ra)*cosd).to(u.mas).value,
yerr=ra_errs.to(u.mas).value, fmt='.', label="Measurements")
plt.ylabel("RA - %s (mas)" % \
refpos.ra.to_string(unit=u.hour, sep='hms',
format='latex', pad=True))
plt.xlabel("MJD")
#plt.legend(loc=4)
plt.legend()
if filebase is not None:
plt.savefig(filebase+"_RA.png")
plt.close()
else:
plt.show()
plt.plot(modelMJDs, [(x[1] - refpos.dec).to(u.mas).value
for x in model_nopsr], 'k-', label="No reflex motion")
plt.plot(modelMJDs, [(x[1] - refpos.dec).to(u.mas).value
for x in model_psr], 'r-', label="With reflex motion")
plt.errorbar(baryMJDs, (decs - refpos.dec).to(u.mas).value,
yerr=dec_errs.to(u.mas).value, fmt='.', label="Measurements")
plt.ylabel("DEC - %s (mas)" % \
refpos.dec.to_string(unit=u.deg, sep='dms',
format='latex', pad=True))
plt.xlabel("MJD")
#plt.legend(loc=1)
plt.legend()
if filebase is not None:
plt.savefig(filebase+"_DEC.png")
plt.close()
else:
plt.show()
def getEarthBaryPosition(jd_tdb):
pos, _ = solsys.solarsystem(jd_tdb, 3, 0)
return pos
ra = initvals['ra']
dec = initvals['dec']
posstring = ra + " " + dec
except KeyError as e:
print "Missing required key ", str(e), " in ", initsfile
sys.exit()
start_pos = coords.SkyCoord(posstring, unit=(u.hourangle, u.deg), frame='icrs')
psr = bp.binary_psr(parfile)
# Get the measurements and convert them to arrays of angles
vlbiepoch, posns, ra_errs, dec_errs, baryMJDs = get_coords(pmparfile)
# This is the Earth position in X, Y, Z (AU) in ICRS wrt SSB
eposns = [solsys.solarsystem(mjd+2400000.5, 3, 0)[0] \
for mjd in baryMJDs]
errs = np.concatenate((ra_errs.to(u.rad).value, dec_errs.to(u.rad).value)) # in radians
ras = np.asarray([pos.ra.rad for pos in posns]) * u.rad
decs = np.asarray([pos.dec.rad for pos in posns]) * u.rad
meas = np.concatenate((ras, decs)) # in radians
try:
pmrasigma = float(initvals['pmra_sigma'])
pmdecsigma = float(initvals['pmdec_sigma'])
pxsigma = float(initvals['px_sigma'])
Omegasigma = float(initvals['Omega_sigma'])
incsigma = float(initvals['inc_sigma'])
rasigma = (float(initvals['ra_sigma'])*u.mas).to(u.rad).value