import numpy as np
import logging
logger = logging.getLogger(__name__)
import so3g
from so3g.proj import coords, quat
import sotodlib.coords.planets as planets
[docs]
def get_sso(aman, sso, nstep=100):
"""
Function for getting xi, eta position of given sso.
Parameters
----------
aman : AxisManager
Input axis manager.
sso : str
Name of input sso.
nstep : int
Number of steps to downsample the TOD.
Returns
-------
xi : array
Array of xi positions.
eta : array
Array of eta positions.
"""
az = aman.boresight.az
el = aman.boresight.el
ctime = aman.timestamps
csl = so3g.proj.CelestialSightLine.az_el(ctime[::nstep], az[::nstep], el[::nstep],
roll=aman.boresight.roll[0], weather="typical")
q_bore = csl.Q
ras, decs = [], []
point_sources = {'tauA': (83.6272579, 22.02159891),
'rcw38': (134.7805107, -47.50911231),
'iras16183-4958': (245.5154, -50.09168292),
'iras19078+0901': (287.5575891, 9.107188994),
'rcw122': (260.0339538, -38.95673421),
'cenA': (201.3625336, -43.00797508),
'3c279': (194.0409868, -5.79174024),
'3c273': (187.2775626, 2.053532671),
'G025.36-00.14': (279.5264042, -6.793169326),
'QSO_J2253+1608': (343.4952422, 16.14301323),
'galactic_center': (-93.5833, -29.0078)}
for d1_unix in ctime[::nstep]:
if sso in point_sources:
ra = point_sources[sso][0]
dec = point_sources[sso][1]
planet = planets.SlowSource(d1_unix*1., float(ra) * coords.DEG,
float(dec) * coords.DEG)
else:
try:
planet = planets.SlowSource.for_named_source(sso, d1_unix*1.)
except ValueError:
break
ra0, dec0 = planet.pos(d1_unix)
ras.append(ra0)
decs.append(dec0)
planet_q = quat.rotation_lonlat(np.array(ras), np.array(decs))
if len(q_bore) != len(planet_q):
raise ValueError("Q vectors have inconsistent lengths")
q_total = ~q_bore * planet_q
xi_p, eta_p, _ = quat.decompose_xieta(np.array(q_total))
return xi_p, eta_p