The gimasterflat recipe

gimasterflat

Synopsis

Create the fiber master flat field and the localization mask.

Description

For detailed information please refer to the GIRAFFE pipeline user manual.

It is available at http://www.eso.org/pipelines.

Constructor

cpl.Recipe("gimasterflat")

Create an object for the recipe gimasterflat.

import cpl
gimasterflat = cpl.Recipe("gimasterflat")

Parameters

gimasterflat.param.fiber_splist

Index list of spectra to use for localization (e.g. 2,10,30-40,55). (str; default: ‘’) [default=””].

gimasterflat.param.fiber_nspec

Number of spectra to localize. (int; default: 0) [default=0].

gimasterflat.param.remove_bias

Enable bias removal (bool; default: True) [default=True].

gimasterflat.param.bsremove_method

Bias removal method (str; default: ‘PROFILE’) [default=”PROFILE”].

gimasterflat.param.bsremove_areas

Bias areas to use (Xl0:Xr0:Yl0:Yr0, … ,Xln:Xrn:Yln:Yrn) (str; default: ‘5:40:0:4095’) [default=”5:40:0:4095”].

gimasterflat.param.bsremove_sigma

Sigma Clipping: sigma threshold factor (float; default: 2.5) [default=2.5].

gimasterflat.param.bsremove_niter

Sigma Clipping: maximum number of iterations (int; default: 5) [default=5].

gimasterflat.param.bsremove_mfrac

Sigma Clipping: minimum fraction of points accepted/total [0.0..1.0] (float; default: 0.8) [default=0.8].

gimasterflat.param.bsremove_xorder

Order of X polynomial fit (CURVE method only) (int; default: 1) [default=1].

gimasterflat.param.bsremove_yorder

Order of Y polynomial fit (CURVE method only) (int; default: 1) [default=1].

gimasterflat.param.bsremove_xstep

Sampling step along X (CURVE method only) (int; default: 1) [default=1].

gimasterflat.param.bsremove_ystep

Sampling step along Y (CURVE method only) (int; default: 1) [default=1].

gimasterflat.param.sloc_mode

Localization mode: Use all spectra or the 5 SIWC spectra (str; default: ‘all’) [default=”all”].

gimasterflat.param.sloc_start

Bin along x-axis (int; default: -1) [default=-1].

gimasterflat.param.sloc_retries

Initial localization detection xbin retries. (int; default: 10) [default=10].

gimasterflat.param.sloc_binsize

Initial localization detection xbin size. (int; default: -1) [default=-1].

gimasterflat.param.sloc_ewidth

Localization detection extra width. (float; default: 1.0) [default=1.0].

gimasterflat.param.sloc_ywidth

Full width [pxl] of the equilizing filter (distance between two adjacent fibers). (int; default: -1) [default=-1].

gimasterflat.param.sloc_center

Method used for mask center computation. (str; default: ‘centroid’) [default=”centroid”].

gimasterflat.param.sloc_norm

Enable spectrum normalization along the dispersion axis. (bool; default: False) [default=False].

gimasterflat.param.sloc_noise

Threshold multiplier. (float; default: 7.0) [default=7.0].

gimasterflat.param.sloc_threshold

Selects thresholding algorithm: local, row or global (str; default: ‘local’) [default=”local”].

gimasterflat.param.sloc_ron

New bias sigma (RON) value for dark subtraction (float; default: -1.0) [default=-1.0].

gimasterflat.param.sloc_yorder

Order of Chebyshev polynomial fit. (int; default: 4) [default=4].

gimasterflat.param.sloc_worder

Order of Chebyshev 2D polynomial fit. (int; default: 2) [default=2].

gimasterflat.param.sloc_sigma

Localization clipping: sigma threshold factor (float; default: 2.5) [default=2.5].

gimasterflat.param.sloc_niter

Localization clipping: number of iterations (int; default: 5) [default=5].

gimasterflat.param.sloc_mfrac

Localization clipping: minimum fraction of points accepted/total. (float; default: 0.9) [default=0.9].

gimasterflat.param.psf_model

PSF profile model: `psfexp’, `psfexp2’ (str; default: ‘psfexp2’) [default=”psfexp2”].

gimasterflat.param.psf_norm

Use normalized pixel values. (bool; default: False) [default=False].

gimasterflat.param.psf_binsize

Size of bin along dispersion axis (int; default: 64) [default=64].

gimasterflat.param.psf_maxwidth

Maximum width of the PSF profile. (float; default: 16.0) [default=16.0].

gimasterflat.param.psf_width

Initial width of the PSF profile. (float; default: 0.0) [default=0.0].

gimasterflat.param.psf_exponent

Exponent of the exponential PSF profile (will not be fitted if > 0). (float; default: -3.0) [default=-3.0].

gimasterflat.param.psf_pfniter

Maximum number of iterations used for the fit of the fiber PSF profile. (int; default: 120) [default=120].

gimasterflat.param.psf_pfntest

Maximum number of tests used for the fit of the fiber PSF profile (int; default: 7) [default=7].

gimasterflat.param.psf_pfdchisq

Minimum chi-square difference used for the fit of the fiber PSF profile. (float; default: 0.001) [default=0.001].

gimasterflat.param.psf_prmfit

2D fit of the PSF profile parameters using a Chebyshev polynomial model. (bool; default: False) [default=False].

gimasterflat.param.psf_yorder

Order of Chebyshev polynomial fit. (int; default: 4) [default=4].

gimasterflat.param.psf_worder

Order of Chebyshev 2D polynomial fit. (int; default: 4) [default=4].

gimasterflat.param.psf_sigma

PSF parameter fitting: sigma threshold factor (float; default: 3.5) [default=3.5].

gimasterflat.param.psf_niter

PSF parameter fitting: number of iterations (int; default: 10) [default=10].

gimasterflat.param.psf_mfrac

PSF parameter fitting: minimum fraction of points accepted/total. (float; default: 0.8) [default=0.8].

gimasterflat.param.extr_method

Extraction method: ‘SUM’, ‘HORNE’ or ‘OPTIMAL’ (str; default: ‘SUM’) [default=”SUM”].

gimasterflat.param.extr_ron

New bias sigma (RON) value for bias and dark corrected image (float; default: -1.0) [default=-1.0].

gimasterflat.param.extr_psfmodel

PSF profile model: `psfexp’, `psfexp2’ (str; default: ‘psfexp2’) [default=”psfexp2”].

gimasterflat.param.extr_psfsigma

Sigma clippging threshold used for rejecting data points during PSF fitting (Horne’s sigma). It is used to reject bad pixels and cosmics. (float; default: 7.0) [default=7.0].

gimasterflat.param.extr_psfniter

Maximum number of iterations used for fitting the PSF profile. (int; default: 2) [default=2].

gimasterflat.param.extr_hewidth

Horne extraction method: Number of extra pixels added to the fiber half-width. (int; default: 2) [default=2].

gimasterflat.param.extr_hmingood

Horne extraction method: Minimum number of points used for the profile fit. It sets the lower limit of data points for the pixel rejection. (int; default: 3) [default=3].

gimasterflat.param.extr_omfrac

Optimal extraction method: Minimum fraction of the data points used for fitting the fiber profiles. It sets the lower limit for the pixel rejection. (float; default: 0.9) [default=0.9].

gimasterflat.param.extr_owfactor

Optimal extraction method: Factor by which the fiber PSF half width is multiplied. Adjacent spectra within this area are assumed to affect the spectrum being extracted. (float; default: 3.0) [default=3.0].

gimasterflat.param.extr_obkgorder

Optimal extraction method: Order of the polynomial background model, which is fitted for each wavelength bin along the spatial direction. (int; default: 2) [default=2].

gimasterflat.param.transmission

Controls the relative fiber transmission computation. (bool; default: True) [default=True].

gimasterflat.param.slight

Controls the scattered light model computation. (bool; default: False) [default=False].

gimasterflat.param.slight_model

Name of the scattered light model to use. (str; default: ‘polynom’) [default=”polynom”].

gimasterflat.param.slight_order

Scattered light model fit X and Y order. (str; default: ‘4,2’) [default=”4,2”].

gimasterflat.param.slight_xstep

Interspectrum region sampling step along the dispersion direction. (int; default: 10) [default=10].

gimasterflat.param.slight_ystep

Interspectrum region sampling step along the spatial direction. (int; default: 1) [default=1].

gimasterflat.param.slight_xslice

Interspectrum region sampling step along the dispersion direction for a specific region. This overrides ‘xstep’ for the given region. (str; default: ‘none’) [default=”none”].

gimasterflat.param.slight_ewidth

Extra width [pixels] added to both sides of a spectrum trace. (float; default: 0.5) [default=0.5].

gimasterflat.param.slight_iswidth

Minimum width [pixels] required for interspectrum regions. (int; default: 2) [default=2].

gimasterflat.param.slight_istrim

Turn off using the first and last interspectrum region. (bool; default: True) [default=True].

gimasterflat.param.slight_phff

Use photometric flat field correction. (bool; default: False) [default=False].

gimasterflat.param.slight_remove

Remove scattered light from the input frame. (bool; default: False) [default=False].

The following code snippet shows the default settings for the available parameters.

import cpl
gimasterflat = cpl.Recipe("gimasterflat")

gimasterflat.param.fiber_splist = ""
gimasterflat.param.fiber_nspec = 0
gimasterflat.param.remove_bias = True
gimasterflat.param.bsremove_method = "PROFILE"
gimasterflat.param.bsremove_areas = "5:40:0:4095"
gimasterflat.param.bsremove_sigma = 2.5
gimasterflat.param.bsremove_niter = 5
gimasterflat.param.bsremove_mfrac = 0.8
gimasterflat.param.bsremove_xorder = 1
gimasterflat.param.bsremove_yorder = 1
gimasterflat.param.bsremove_xstep = 1
gimasterflat.param.bsremove_ystep = 1
gimasterflat.param.sloc_mode = "all"
gimasterflat.param.sloc_start = -1
gimasterflat.param.sloc_retries = 10
gimasterflat.param.sloc_binsize = -1
gimasterflat.param.sloc_ewidth = 1.0
gimasterflat.param.sloc_ywidth = -1
gimasterflat.param.sloc_center = "centroid"
gimasterflat.param.sloc_norm = False
gimasterflat.param.sloc_noise = 7.0
gimasterflat.param.sloc_threshold = "local"
gimasterflat.param.sloc_ron = -1.0
gimasterflat.param.sloc_yorder = 4
gimasterflat.param.sloc_worder = 2
gimasterflat.param.sloc_sigma = 2.5
gimasterflat.param.sloc_niter = 5
gimasterflat.param.sloc_mfrac = 0.9
gimasterflat.param.psf_model = "psfexp2"
gimasterflat.param.psf_norm = False
gimasterflat.param.psf_binsize = 64
gimasterflat.param.psf_maxwidth = 16.0
gimasterflat.param.psf_width = 0.0
gimasterflat.param.psf_exponent = -3.0
gimasterflat.param.psf_pfniter = 120
gimasterflat.param.psf_pfntest = 7
gimasterflat.param.psf_pfdchisq = 0.001
gimasterflat.param.psf_prmfit = False
gimasterflat.param.psf_yorder = 4
gimasterflat.param.psf_worder = 4
gimasterflat.param.psf_sigma = 3.5
gimasterflat.param.psf_niter = 10
gimasterflat.param.psf_mfrac = 0.8
gimasterflat.param.extr_method = "SUM"
gimasterflat.param.extr_ron = -1.0
gimasterflat.param.extr_psfmodel = "psfexp2"
gimasterflat.param.extr_psfsigma = 7.0
gimasterflat.param.extr_psfniter = 2
gimasterflat.param.extr_hewidth = 2
gimasterflat.param.extr_hmingood = 3
gimasterflat.param.extr_omfrac = 0.9
gimasterflat.param.extr_owfactor = 3.0
gimasterflat.param.extr_obkgorder = 2
gimasterflat.param.transmission = True
gimasterflat.param.slight = False
gimasterflat.param.slight_model = "polynom"
gimasterflat.param.slight_order = "4,2"
gimasterflat.param.slight_xstep = 10
gimasterflat.param.slight_ystep = 1
gimasterflat.param.slight_xslice = "none"
gimasterflat.param.slight_ewidth = 0.5
gimasterflat.param.slight_iswidth = 2
gimasterflat.param.slight_istrim = True
gimasterflat.param.slight_phff = False
gimasterflat.param.slight_remove = False

You may also set or overwrite some or all parameters by the recipe parameter param, as shown in the following example:

import cpl
gimasterflat = cpl.Recipe("gimasterflat")
[...]
res = gimasterflat( ..., param = {"fiber_splist":"", "fiber_nspec":0})

See also

cpl.Recipe for more information about the recipe object.

Bug reports

Please report any problems to Giraffe Pipeline. Alternatively, you may send a report to the ESO User Support Department.