Source code for gammapy.irf.irf_reduce

# Licensed under a 3-clause BSD style license - see LICENSE.rst
import logging
from .psf_table import EnergyDependentTablePSF

__all__ = ["make_psf", "make_mean_psf"]

log = logging.getLogger(__name__)


[docs]def make_psf(observation, position, energy=None, rad=None): """Make energy-dependent PSF for a given source position. Parameters ---------- observation : `~gammapy.data.Observation` Observation for which to compute the PSF position : `~astropy.coordinates.SkyCoord` Position at which to compute the PSF energy : `~astropy.units.Quantity` 1-dim energy array for the output PSF. If none is given, the energy array of the PSF from the observation is used. rad : `~astropy.coordinates.Angle` 1-dim offset wrt source position array for the output PSF. If none is given, the offset array of the PSF from the observation is used. Returns ------- psf : `~gammapy.irf.EnergyDependentTablePSF` Energy dependent psf table """ offset = position.separation(observation.pointing_radec) if energy is None: energy = observation.psf.to_energy_dependent_table_psf(theta=offset).energy if rad is None: rad = observation.psf.to_energy_dependent_table_psf(theta=offset).rad psf_value = observation.psf.to_energy_dependent_table_psf( theta=offset, rad=rad ).evaluate(energy) arf = observation.aeff.data.evaluate(offset=offset, energy_true=energy) exposure = arf * observation.observation_live_time_duration psf = EnergyDependentTablePSF( energy=energy, rad=rad, exposure=exposure, psf_value=psf_value ) return psf
[docs]def make_mean_psf(observations, position, energy=None, rad=None): """Compute mean energy-dependent PSF. Parameters ---------- observations : `~gammapy.data.Observations` Observations for which to compute the PSF position : `~astropy.coordinates.SkyCoord` Position at which to compute the PSF energy : `~astropy.units.Quantity` 1-dim energy array for the output PSF. If none is given, the energy array of the PSF from the first observation is used. rad : `~astropy.coordinates.Angle` 1-dim offset wrt source position array for the output PSF. If none is given, the energy array of the PSF from the first observation is used. Returns ------- psf : `~gammapy.irf.EnergyDependentTablePSF` Mean PSF """ for idx, observation in enumerate(observations): psf = make_psf(observation, position, energy, rad) if idx == 0: stacked_psf = psf else: stacked_psf = stacked_psf.stack(psf) return stacked_psf