DataStoreObservation

class gammapy.data.DataStoreObservation(obs_id, data_store, obs_filter=None)[source]

Bases: gammapy.data.Observation

IACT data store observation.

Parameters
obs_idint

Observation ID

data_storeDataStore

Data store

obs_filterObservationFilter, optional

Filter for the observation

Attributes Summary

aeff

Load effective area object.

bkg

Load background object.

edisp

Load energy dispersion object.

events

Load gammapy.data.EventList object and apply the filter.

fixed_pointing_info

Fixed pointing info for this observation (FixedPointingInfo).

gti

Load gammapy.data.GTI object and apply the filter.

muoneff

Observation muon efficiency.

obs_info

Observation information (dict).

observation_dead_time_fraction

Dead-time fraction (float).

observation_live_time_duration

Live-time duration in seconds (Quantity).

observation_time_duration

Observation time duration in seconds (Quantity).

observatory_earth_location

Observatory location (EarthLocation).

pointing_altaz

Pointing ALT / AZ sky coordinates (SkyCoord).

pointing_radec

Pointing RA / DEC sky coordinates (SkyCoord).

pointing_zen

Pointing zenith angle sky (Quantity).

psf

Load point spread function object.

target_radec

Target RA / DEC sky coordinates (SkyCoord).

tstart

Observation start time (Time).

tstop

Observation stop time (Time).

Methods Summary

check(self[, checks])

Run checks.

create(pointing[, obs_id, livetime, tstart, …])

Create an observation.

from_caldb(pointing[, obs_id, livetime, …])

Create an observation using IRFs from a given CTA CALDB.

load(self[, hdu_type, hdu_class])

Load data file as appropriate object.

location(self[, hdu_type, hdu_class])

HDU location object.

peek(self[, figsize])

Quick-look plots in a few panels.

select_time(self, time_interval)

Select a time interval of the observation.

Attributes Documentation

aeff

Load effective area object.

bkg

Load background object.

edisp

Load energy dispersion object.

events

Load gammapy.data.EventList object and apply the filter.

fixed_pointing_info

Fixed pointing info for this observation (FixedPointingInfo).

gti

Load gammapy.data.GTI object and apply the filter.

muoneff

Observation muon efficiency.

obs_info

Observation information (dict).

observation_dead_time_fraction

Dead-time fraction (float).

Defined as dead-time over observation time.

Dead-time is defined as the time during the observation where the detector didn’t record events: https://en.wikipedia.org/wiki/Dead_time https://ui.adsabs.harvard.edu/abs/2004APh….22..285F

The dead-time fraction is used in the live-time computation, which in turn is used in the exposure and flux computation.

observation_live_time_duration

Live-time duration in seconds (Quantity).

The dead-time-corrected observation time.

Computed as t_live = t_observation * (1 - f_dead) where f_dead is the dead-time fraction.

observation_time_duration

Observation time duration in seconds (Quantity).

The wall time, including dead-time.

observatory_earth_location

Observatory location (EarthLocation).

pointing_altaz

Pointing ALT / AZ sky coordinates (SkyCoord).

pointing_radec

Pointing RA / DEC sky coordinates (SkyCoord).

pointing_zen

Pointing zenith angle sky (Quantity).

psf

Load point spread function object.

target_radec

Target RA / DEC sky coordinates (SkyCoord).

tstart

Observation start time (Time).

tstop

Observation stop time (Time).

Methods Documentation

check(self, checks='all')[source]

Run checks.

This is a generator that yields a list of dicts.

classmethod create(pointing, obs_id=0, livetime=None, tstart=None, tstop=None, irfs=None, deadtime_fraction=0.0)

Create an observation.

User must either provide the livetime, or the start and stop times.

Parameters
pointingSkyCoord

Pointing position

obs_idint

Observation ID as identifier

livetime~astropy.units.Quantity`

Livetime exposure of the simulated observation

tstartQuantity

Start time of observation

tstopQuantity

Stop time of observation

irfsdict

IRFs used for simulating the observation: bkg, aeff, psf, edisp

deadtime_fractionfloat, optional

Deadtime fraction, defaults to 0

Returns
obsgammapy.data.MemoryObservation
classmethod from_caldb(pointing, obs_id=None, livetime=None, tstart=None, tstop=None, caldb='prod2', irf='South0.5hr', deadtime_fraction=0.0)

Create an observation using IRFs from a given CTA CALDB.

Parameters
pointingSkyCoord

Pointing position

obs_idint

Observation ID as identifier

livetime~astropy.units.Quantity`

Livetime exposure of the simulated observation

tstartQuantity

Start time of observation

tstopQuantity

Stop time of observation

caldbstr

Calibration database

irfstr

Type of Instrumental response function.

deadtime_fractionfloat, optional

Deadtime fraction, defaults to 0

Returns
obsgammapy.data.Observation
load(self, hdu_type=None, hdu_class=None)[source]

Load data file as appropriate object.

Parameters
hdu_typestr

HDU type (see VALID_HDU_TYPE)

hdu_classstr

HDU class (see VALID_HDU_CLASS)

Returns
objectobject

Object depends on type, e.g. for events it’s a EventList.

location(self, hdu_type=None, hdu_class=None)[source]

HDU location object.

Parameters
hdu_typestr

HDU type (see VALID_HDU_TYPE)

hdu_classstr

HDU class (see VALID_HDU_CLASS)

Returns
locationHDULocation

HDU location

peek(self, figsize=(12, 10))

Quick-look plots in a few panels.

Parameters
figszietuple

Figure size

select_time(self, time_interval)[source]

Select a time interval of the observation.

Parameters
time_intervalastropy.time.Time

Start and stop time of the selected time interval. For now we only support a single time interval.

Returns
new_obsDataStoreObservation

A new observation instance of the specified time interval