def show_projection(self, track, axes=True, max_theta=30., X_mark=None):
"""
Obtain the polar coordinates of a shower track relative to a telescope
position in both horizontal and FoV coordinates systems and determine
the fraction of the track within the telescope field of view.
In addition, show the projection of the shower track as viewed by the
telescope.
Parameters
----------
track : Track object or Shower object.
axes : bool, default True
Show the axes of both coordinate systems of reference.
max_theta : float, default 30 degrees
Maximum offset angle in degrees relative to the telescope
pointing direction.
X_mark : float
Reference slant depth in g/cm^2 of the shower track to be
marked in the figure. If None, no mark is included.
Returns
-------
Projection object.
(ax1, ax2) : PolarAxesSubplot objects.
See also
--------
Projection.show
"""
projection = sm.Projection(self, track)
from ._tools import show_projection
return projection, (show_projection(projection, None, False, axes,
max_theta, X_mark))
def Projection(self, track):
"""
Obtain the coordinates of a shower track relative to the telescope
position in both zenith and camera projection and determine the
fraction of the track within the telescope field of view.
Parameters
----------
track : Track object or Shower object.
Returns
-------
Projection object.
See also
--------
Projection.show
"""
return sm.Projection(self, track)
def Projection(self, telescope):
"""
Obtain the coordinates of a shower track relative to a telescope
position in both zenith and camera projection and determine the
fraction of the track within the telescope field of view.
Parameters
----------
telescope : Telescope object.
Returns
-------
Projection object.
(ax1, ax2) : AxesSubplot objects.
See also
--------
Projection.show
"""
return sm.Projection(telescope, self.track)
def show_projection(self,
telescope,
shower_size=True,
axes=True,
max_theta=30.,
X_mark='X_max'):
"""
Make a Projection object and show it.
Parameters
----------
telescope : Telescope object.
shower_size : book, default True
Make the radii of the shower track points proportional to the
shower size.
axes : book, default True
Show the axes of both frames of reference.
max_theta : float, default 30 degrees
Maximum offset angle in degrees relative to the telescope
pointing direction.
X_mark : float
Reference slant depth in g/cm^2 of the shower track to be ma
ked in the figure, default X_max. If X_mark=None, no mark is
included.
Returns
-------
Projection object.
(ax1, ax2) : PolarAxesSubpot objects.
See also
--------
Projection.show
"""
if X_mark == 'X_max':
X_mark = self.X_max
projection = sm.Projection(telescope, self.track)
profile = self.profile
from ._tools import show_projection
return projection, (show_projection(projection, profile, shower_size,
axes, max_theta, X_mark))
def Signal(telescope,
shower,
projection=None,
atm_trans=True,
tel_eff=True,
**kwargs):
"""
Calculate the signal produced by a shower detected by a telescope.
Parameters
----------
telescope : Telescope object.
shower : Shower object.
projection : Projection object
If None, it will generated from telescope and shower.
atm_trans : bool, default True
Include the atmospheric transmision to transport photons.
tel_eff : bool, default True
Include the telescope efficiency to calculate the signal. If False,
100% efficiency is assumed for a given wavelenght interval.
**kwargs {wvl_ini, wvl_fin, wvl_step}
These parameters will modify the wavelenght interval when
tel_eff==False. If None, the wavelength interval defined in the
telescope is used.
Returns
-------
signal : Signal object.
"""
from .telescope import _Telescope
from .shower import _Shower
if not isinstance(telescope, _Telescope):
if not isinstance(telescope, _Shower):
raise ValueError('The input telescope is not valid')
else:
telescope, shower = (shower, telescope)
if not isinstance(shower, _Shower):
raise ValueError('The input shower is not valid')
# This function is normally called from Event. If not, projection must be
# generated.
from .projection import _Projection
if not isinstance(projection, _Projection):
projection = sm.Projection(telescope, shower.track)
atmosphere = shower.atmosphere
track = shower.track
fluorescence = shower.fluorescence
cherenkov = shower.cherenkov
signal = _Signal()
signal.shower = shower
signal.telescope = telescope
signal.projection = projection
signal.atmosphere = atmosphere
signal.track = track
signal.profile = shower.profile
signal.fluorescence = fluorescence
signal.cherenkov = cherenkov
signal.atm_trans = atm_trans
signal.tel_eff = tel_eff
if tel_eff:
# Wavelenght range to calculate the signal
wvl_ini = telescope.wvl_ini
wvl_fin = telescope.wvl_fin
wvl_step = telescope.wvl_step
wvl_cher = telescope.wvl_cher
eff_fluo = telescope.eff_fluo
eff_cher = telescope.eff_cher
else:
# User-defined wavalength range
wvl_ini = kwargs.get('wvl_ini', telescope.wvl_ini)
wvl_fin = kwargs.get('wvl_fin', telescope.wvl_fin)
wvl_step = kwargs.get('wvl_step', telescope.wvl_step)
wvl_cher = np.arange(wvl_ini, wvl_fin, wvl_step)
signal.wvl_ini = wvl_ini
signal.wvl_fin = wvl_fin
signal.wvl_step = wvl_step
# Only discretization points within the telescope field of view contributes
# to the signal. In addition, the very begninning of the shower profile is
# ignored to speed up calculations
points = projection[projection.FoV & (signal.profile.s > 0.01)].index
distance = np.array(projection.distance.loc[points])
theta = np.radians(projection.theta.loc[points])
alt = np.radians(projection.alt.loc[points])
# Solid angle fraction covered by the telescope area. Only discretization
# points within the telescope field of view contributes to the signal
collection = (telescope.area * np.cos(theta) / 4000000. / np.pi /
distance**2)
# Collection efficiency for the angular distribution of Cherenkov light
# See F. Nerling et al., Astropart. Phys. 24(2006)241.
beta = np.radians(projection.beta.loc[points])
theta_c = np.radians(cherenkov.theta_c.loc[points])
theta_cc = np.radians(cherenkov.theta_cc.loc[points])
a = np.array(cherenkov.a.loc[points])
b = np.array(cherenkov.b.loc[points])
collection_cher = collection * 2. / np.sin(beta) * (
a / theta_c * np.exp(-beta / theta_c) +
b / theta_cc * np.exp(-beta / theta_cc))
# Relative fluorescence contribution from each shower point at each band
# (between wvl_ini and wvl_fin). The atmospheric transmission is included
# later
rel_fluo = fluorescence.loc[points]
if tel_eff:
rel_fluo *= eff_fluo # 34 bands
# Selection of bands within the wavelenght range
rel_fluo = rel_fluo.loc[:, wvl_ini:wvl_fin]
if atm_trans:
# Atmospheric transmission at 350 nm. Only Rayleigh scattering is
# considered
X_vert = np.array(atmosphere.X_vert.loc[points])
rho = np.array(atmosphere.rho.loc[points])
thickness = np.array(
atmosphere.h_to_Xv(atmosphere.h0 + telescope.z) - X_vert)
thickness[thickness != 0] = (thickness[thickness != 0] /
np.sin(alt[thickness != 0]))
thickness[thickness == 0] = (100000. * distance[thickness == 0] *
rho[thickness == 0])
# Only points within the telescope FoV, otherwise trans=0
trans = np.exp(-thickness / 1645.)
# Relative fluorescence contribution including atmospheric transmission
for wvl in rel_fluo:
rel_fluo[wvl] *= trans**((350. / wvl)**4)
# Wavelenght factor for Cherenkov contribution to signal from each
# shower point
wvl_factor = pd.DataFrame(index=points)
for wvl in wvl_cher:
wvl_factor[wvl] = trans**((350. / wvl)**4) / wvl**2
# wvl**2 -> (wvl**2 - wvl_step**2 / 4.)
if tel_eff:
wvl_factor *= eff_cher
wvl_factor = wvl_factor.sum(axis=1) * wvl_step / (1. / 290. -
1. / 430.)
elif tel_eff: # If atmospheric transmission is not included
# The wavelength factor of Cherenkov signal is the same for all
# shower points
wvl_factor = eff_cher / wvl_cher**2
# wvl_cher**2 -> (wvl_cher**2 - wvl_step**2 / 4.)
wvl_factor = wvl_factor.sum() * wvl_step / (1. / 290. - 1. / 430.)
# If neither the atmospheric transmission nor the telescope efficiency are
# included
else:
# The wavelength factor of Cherenkov signal only depends on the
# integration wavelength interval
wvl_factor = (1. / wvl_ini - 1. / wvl_fin) / (1. / 290. - 1. / 430.)
# Number of photoelectrons due to fluorescence light emitted from each
# shower point
signal['Npe_fluo'] = rel_fluo.sum(axis=1) * collection
# Number of photoelectrons due to fluorescence light within the FoV
signal.Npe_fluo_sum = signal.Npe_fluo.sum()
# Number of photoelectrons due to Cherenkov light emitted from each shower
# point
signal['Npe_cher'] = (cherenkov.N_ph.loc[points] * collection_cher *
wvl_factor)
# Number of photoelectrons due to Cherenkov light within the FoV
signal.Npe_cher_sum = signal.Npe_cher.sum()
# Total number of photoelectrons from both light components emitted at each
# shower point
signal['Npe_total'] = signal.sum(axis=1)
# Total number of photoelectrons
signal.Npe_total_sum = signal.Npe_cher_sum + signal.Npe_fluo_sum
return signal
def Event(observatory, shower, atm_trans=True, tel_eff=True, **kwargs):
"""
Construct an Event object from a shower and an observatory.
The Event objet contains the signal produced by the shower in each
telescope of the observatory.
Parameters
----------
observatory : Observatory object (may be a Grid object).
shower : Shower object.
atm_trans : bool, default True
Include the atmospheric transmision to transport photons.
tel_eff : bool, default True
Include the telescope efficiency to calculate the signals.
If False, 100% efficiency is assumed for a given wavelength interval.
**kwargs {wvl_ini, wvl_fin, wvl_step}
These parameters will be passed to the Signal constructor to modify
the wavelength interval when tel_eff==False. If None, the wavelength
interval defined in each telescope is used.
Returns
-------
event : Event object.
"""
from .observatory import _Observatory, _Grid
from .telescope import _Telescope
from .shower import _Shower
if not isinstance(shower, _Shower):
observatory, shower = (shower, observatory)
if not isinstance(shower, _Shower):
raise ValueError('The input shower is not valid')
if isinstance(observatory, (_Telescope, _Observatory)):
if isinstance(observatory, _Grid):
event = _GridEvent()
event.grid = observatory
else:
event = _Event()
if isinstance(observatory, _Telescope):
telescope = observatory
event.observatory = _Observatory()
event.observatory.append(telescope)
else:
event.observatory = observatory
else:
raise ValueError('The input observatory is not valid')
event.shower = shower
event.atmosphere = shower.atmosphere
event.track = shower.track
event.profile = shower.profile
event.cherenkov = shower.cherenkov
event.fluorescence = shower.fluorescence
event.atm_trans = atm_trans
event.tel_eff = tel_eff
event.projections = []
event.signals = []
for telescope in observatory:
projection = sm.Projection(telescope, event.track)
event.projections.append(projection)
signal = sm.Signal(telescope, shower, projection, atm_trans, tel_eff,
**kwargs)
event.signals.append(signal)
event.images = None
return event