SeeingModel¶
- class rubin_sim.site_models.SeeingModel(filter_list=['u', 'g', 'r', 'i', 'z', 'y'], eff_wavelens=None, telescope_seeing=0.25, optical_design_seeing=0.08, camera_seeing=0.3, raw_seeing_wavelength=500, efd_seeing='FWHM_500')¶
Bases:
object
LSST FWHM calculations for FWHM_effective and FWHM_geometric.
Calculations of the delivered values are based on equations in Document-20160 (“Atmospheric and Delivered Image Quality in OpSim” by Bo Xin, George Angeli, Zeljko Ivezic) An example of the calculation of delivered image seeing from DIMM FWHM_500 is available in https://smtn-002.lsst.io/#calculating-m5-values-in-the-lsst-operations-simulator
- Parameters:
- filter_list
list
[str
], opt List of the filter bandpasses for which to calculate delivered FWHM_effective and FWHM_geometric Default [‘u’, ‘g’, ‘r’, ‘i’, ‘z’, ‘y’]
- eff_wavelens
list
[float
] or None, opt Effective wavelengths for those bandpasses, in nanometers. If None, the SeeingModel will read the throughput curves from disk ($RUBIN_SIM_DATA_DIR/throughputs/baseline/total_[f].dat) and calculate effective wavelengths.
- telescope_seeing
float
, opt The contribution to the delivered FWHM from the telescope, in arcseconds. Default 0.25”
- optical_design_seeing
float
, opt The contribution to the seeing from the optical design, in arcseconds. Default 0.08 arcseconds
- camera_seeing
float
, opt The contribution to the seeing from the camera, in arcseconds. Default 0.30 arcseconds
- raw_seeing_wavelength
float
, opt The wavelength of the DIMM-delivered equivalent FWHM, in nanometers. Default 500nm.
- efd_seeing
str
, opt The name of the DIMM FWHM measurements in the efd / conditions object. Default
FWHM_500
- filter_list
Methods Summary
__call__
(fwhm_z, airmass)Calculate the seeing values FWHM_eff and FWHM_geom at the given airmasses, for the specified effective wavelengths, given FWHM_zenith (typically FWHM_500).
Deprecated.
Deprecated.
fwhm_eff_to_fwhm_geom
(fwhm_eff)Calculate FWHM_geom from FWHM_eff.
fwhm_geom_to_fwhm_eff
(fwhm_geom)Calculate FWHM_eff from FWHM_geom.
Methods Documentation
- __call__(fwhm_z, airmass)¶
Calculate the seeing values FWHM_eff and FWHM_geom at the given airmasses, for the specified effective wavelengths, given FWHM_zenith (typically FWHM_500).
FWHM_geom represents the geometric size of the PSF; FWHM_eff represents the FWHM of a single gaussian which encloses the same number of pixels as N_eff (the number of pixels enclosed in the actual PSF – this is the value to use when calculating SNR).
FWHM_geom(”) = 0.822 * FWHM_eff(”) + 0.052”
The FWHM_eff includes a contribution from the system and from the atmosphere. Both of these are expected to scale with airmass^0.6 and with (500(nm)/wavelength(nm))^0.3. FWHM_eff = 1.16 * sqrt(FWHM_sys**2 + 1.04*FWHM_atm**2)
- Parameters:
- fwhm_z: `float`, or efdData `dict`
FWHM at zenith (arcsec).
- airmass: `float`, `np.array`, or targetDict `dict`
Airmass (unitless).
- Returns:
- FWHMeff, FWHMGeom
dict
of {numpy.ndarray
,numpy.ndarray
} FWHMeff, FWHMgeom: both are the same shape numpy.ndarray. If airmass is a single value, FWHMeff & FWHMgeom are 1-d arrays, with the same order as eff_wavelen (i.e. eff_wavelen[0] = u, then FWHMeff[0] = u). If airmass is a numpy array, FWHMeff and FWHMgeom are 2-d arrays, in the order of <filter><airmass> (i.e. eff_wavelen[0] = u, 1-d array over airmass range).
- FWHMeff, FWHMGeom
- config_info()¶
Deprecated. Report configuration parameters and version information.
- configure()¶
Deprecated. Configure through the init method.
- static fwhm_eff_to_fwhm_geom(fwhm_eff)¶
Calculate FWHM_geom from FWHM_eff.