def LN_ICRS_to_AltAz(self,ra=None,dec=None,ln_pressure_qfe=None,ln_temperature=None,ln_humidity=None,obstime=None,mount_set_icrs=True):
ln_pos_eq.ra=ra
ln_pos_eq.dec=dec
if mount_set_icrs:
# libnova corrections for catalog data ...
# ToDo missing see Jean Meeus, Astronomical Algorithms, chapter 23
# proper motion
# annual paralax (0".8)
# gravitational deflection of light (0".003)
ln.ln_get_equ_prec(byref(ln_pos_eq), c_double(obstime.jd), byref(ln_pos_eq_pr))
ln_pos_eq_nut=self.LN_nutation_meeus(eq_pr=ln_pos_eq_pr,JD=obstime.jd)
ln.ln_get_equ_aber(byref(ln_pos_eq_nut), c_double(obstime.jd), byref(ln_pos_eq_ab))
ln.ln_get_hrz_from_equ(byref(ln_pos_eq_ab), byref(self.ln_obs), c_double(obstime.jd), byref(ln_pos_aa_ab))
# here we use QFE not pressure at sea level!
# E.g. at Dome-C this formula:
# ln_pressure=ln_see_pres * pow(1. - (0.0065 * ln_alt) / 288.15, (9.80665 * 0.0289644) / (8.31447 * 0.0065));
# is not precise.
if self.refraction_method is None:
d_alt_deg=ln.ln_get_refraction_adj(c_double(ln_pos_aa_ab.alt),c_double(ln_pressure_qfe),c_double(ln_temperature))
else:
d_alt_deg=180./np.pi* self.refraction_method(alt=ln_pos_aa_ab.alt,tem=ln_temperature,pre=ln_pressure_qfe,hum=ln_humidity)
else:
# ... but not for the star position as measured in mount frame
ln.ln_get_hrz_from_equ(byref(ln_pos_eq), byref(self.ln_obs), c_double(obstime.jd), byref(ln_pos_aa_ab));
d_alt_deg=0.
a_az=Longitude(ln_pos_aa_ab.az,u.deg)
a_az.wrap_at(0.*u.degree)
a_alt=Latitude(ln_pos_aa_ab.alt + d_alt_deg,u.deg)
pos_aa=SkyCoord(az=a_az.radian,alt=a_alt.radian,unit=(u.radian,u.radian),frame='altaz',location=self.obs,obstime=obstime,obswl=0.5*u.micron, pressure=ln_pressure_qfe*u.hPa,temperature=ln_temperature*u.deg_C,relative_humidity=ln_humidity)
return pos_aa
def LN_ICRS_to_AltAz(self,
ra=None,
dec=None,
ln_pressure_qfe=None,
ln_temperature=None,
ln_humidity=None,
obstime=None,
mount_set_icrs=True):
ln_pos_eq.ra = ra
ln_pos_eq.dec = dec
if mount_set_icrs:
# libnova corrections for catalog data ...
# ToDo missing see Jean Meeus, Astronomical Algorithms, chapter 23
# proper motion
# annual paralax (0".8)
# gravitational deflection of light (0".003)
ln.ln_get_equ_prec(byref(ln_pos_eq), c_double(obstime.jd),
byref(ln_pos_eq_pr))
ln_pos_eq_nut = self.LN_nutation_meeus(eq_pr=ln_pos_eq_pr,
JD=obstime.jd)
ln.ln_get_equ_aber(byref(ln_pos_eq_nut), c_double(obstime.jd),
byref(ln_pos_eq_ab))
ln.ln_get_hrz_from_equ(byref(ln_pos_eq_ab), byref(self.ln_obs),
c_double(obstime.jd), byref(ln_pos_aa_ab))
# here we use QFE not pressure at sea level!
# E.g. at Dome-C this formula:
# ln_pressure=ln_see_pres * pow(1. - (0.0065 * ln_alt) / 288.15, (9.80665 * 0.0289644) / (8.31447 * 0.0065));
# is not precise.
if self.refraction_method is None:
d_alt_deg = ln.ln_get_refraction_adj(
c_double(ln_pos_aa_ab.alt), c_double(ln_pressure_qfe),
c_double(ln_temperature))
else:
d_alt_deg = 180. / np.pi * self.refraction_method(
alt=ln_pos_aa_ab.alt,
tem=ln_temperature,
pre=ln_pressure_qfe,
hum=ln_humidity)
else:
# ... but not for the star position as measured in mount frame
ln.ln_get_hrz_from_equ(byref(ln_pos_eq), byref(self.ln_obs),
c_double(obstime.jd), byref(ln_pos_aa_ab))
d_alt_deg = 0.
a_az = Longitude(ln_pos_aa_ab.az, u.deg)
a_az.wrap_at(0. * u.degree)
a_alt = Latitude(ln_pos_aa_ab.alt + d_alt_deg, u.deg)
pos_aa = SkyCoord(az=a_az.radian,
alt=a_alt.radian,
unit=(u.radian, u.radian),
frame='altaz',
location=self.obs,
obstime=obstime,
obswl=0.5 * u.micron,
pressure=ln_pressure_qfe * u.hPa,
temperature=ln_temperature * u.deg_C,
relative_humidity=ln_humidity)
return pos_aa
def plot(self):
ra = Longitude([x.cat_ic.ra.radian for x in self.cats], unit=u.radian)
ra = ra.wrap_at(180. * u.degree)
dec = Latitude([x.cat_ic.dec.radian for x in self.cats], unit=u.radian)
import matplotlib.mlab as mlab
import matplotlib
# this varies from distro to distro:
matplotlib.rcParams["backend"] = "TkAgg"
import matplotlib.mlab as mlab
import matplotlib.pyplot as plt
plt.ioff()
fig = plt.figure(figsize=(8, 6))
ax = fig.add_subplot(111, projection='mollweide')
# eye candy
mag_min = min([x.mag_v for x in self.cats])
mag_max = max([x.mag_v for x in self.cats])
npa = np.asarray([
np.power(2.512, (x.mag_v - mag_min) / (mag_max - mag_min)) * 5.
for x in self.cats
])
ax.set_title(
'selected stars for observatory latitude: {0:.2f} deg'.format(
self.obs.latitude.degree))
ax.scatter(ra.radian, dec.radian, s=npa)
ax.set_xticklabels([
'14h', '16h', '18h', '20h', '22h', '0h', '2h', '4h', '6h', '8h',
'10h'
])
ax.grid(True)
plt.show()
def coordinates(self, coord_type='world', origin=0, mode='center'):
"""
Sky coordinate images.
Parameters
----------
coord_type : {'world', 'pix', 'skycoord'}
Which type of coordinates to return.
origin : {0, 1}
Pixel coordinate origin.
mode : {'center', 'edges'}
Return coordinate values at the pixels edges or pixel centers.
"""
if mode == 'center':
y, x = np.indices(self.data.shape)
elif mode == 'edges':
shape = self.data.shape[0] + 1, self.data.shape[1] + 1
y, x = np.indices(shape)
y, x = y - 0.5, x - 0.5
else:
raise ValueError('Invalid mode to compute coordinates.')
if coord_type == 'pix':
return x, y
else:
xsky, ysky = self.wcs.wcs_pix2world(x, y, origin)
l, b = Longitude(xsky, unit='deg'), Latitude(ysky, unit='deg')
l = l.wrap_at('180d')
if coord_type == 'world':
return l.degree, b.degree
elif coord_type == 'skycoord':
return l, b
else:
raise ValueError("Not a valid coordinate type. Choose either"
" 'world', 'pix' or 'skycoord'.")