The kmo_illumination_flat recipe

kmo_illumination_flat

Synopsis

Alternative to kmo_illumination based on flatfield frames.

Description

This recipe creates the spatial non-uniformity calibration frame needed for all three detectors. It must be called after the kmo_wave_cal-recipe, which generates the spectral calibration frame needed in this recipe. As input at least a flatfield frame is required.

Contrary to kmo_illumination it doesn’t use flat sky frames but rather the flatfield frames from the internal flat lamp. This recipe can be used if no acceptable flat sky frames are available.

The created product, the illumination correction, can be used as input for kmo_std_star and kmo_sci_red.

Input files

DO                    KMOS
category              Type   Explanation                    Required #Frames
--------              -----  -----------                    -------- -------
FLAT_SKY_FLAT          F2D   Flatlamp-on exposures             Y      1-n
                             (at least 3 frames recommended)
XCAL                   F2D   x calibration frame               Y       1
YCAL                   F2D   y calibration frame               Y       1
LCAL                   F2D   Wavelength calib. frame           Y       1
WAVE_BAND              F2L   Table with start-/end-wavelengths Y       1

Output files

DO                    KMOS
category              Type   Explanation
--------              -----  -----------
ILLUM_CORR             F2I    Illumination calibration frame

Constructor

cpl.Recipe("kmo_illumination_flat")

Create an object for the recipe kmo_illumination_flat.

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

Parameters

kmo_illumination_flat.param.imethod

Method to use for interpolation: [“NN” (nearest neighbour), “lwNN” (linear weighted nearest neighbor), “swNN” (square weighted nearest neighbor), “MS” (Modified Shepard’s method), “CS” (Cubic spline)] (str; default: ‘CS’) [default=”CS”].

kmo_illumination_flat.param.neighborhoodRange

Defines the range to search for neighbors. in pixels (float; default: 1.001) [default=1.001].

kmo_illumination_flat.param.flux

TRUE: Apply flux conservation. FALSE: otherwise (bool; default: False) [default=False].

kmo_illumination_flat.param.pix_scale

Change the pixel scale [arcsec]. Default of 0.2” results into cubes of 14x14pix, a scale of 0.1” results into cubes of 28x28pix, etc. (float; default: 0.2) [default=0.2].

kmo_illumination_flat.param.suppress_extension

Suppress arbitrary filename extension. (TRUE (apply) or FALSE (don’t apply) (bool; default: False) [default=False].

kmo_illumination_flat.param.b_samples

The number of samples in wavelength for the reconstructed cube (long; default: 2048) [default=2048].

kmo_illumination_flat.param.b_start

The lowest wavelength [um] to use when reconstructing. Derived by default, depending on the band (float; default: -1.0) [default=-1.0].

kmo_illumination_flat.param.b_end

The highest wavelength [um] to use when reconstructing. Derived by default, depending on the band (float; default: -1.0) [default=-1.0].

kmo_illumination_flat.param.cmethod

Apply “average”, “median”, “sum”, “min_max.” or “ksigma”. (str; default: ‘ksigma’) [default=”ksigma”].

kmo_illumination_flat.param.cpos_rej

The positive rejection threshold for kappa-sigma-clipping (sigma). (float; default: 3.0) [default=3.0].

kmo_illumination_flat.param.cneg_rej

The negative rejection threshold for kappa-sigma-clipping (sigma). (float; default: 3.0) [default=3.0].

kmo_illumination_flat.param.citer

The number of iterations for kappa-sigma-clipping. (long; default: 3) [default=3].

kmo_illumination_flat.param.cmax

The number of maximum pixel values to clip with min/max-clipping. (long; default: 1) [default=1].

kmo_illumination_flat.param.cmin

The number of minimum pixel values to clip with min/max-clipping. (long; default: 1) [default=1].

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

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

kmo_illumination_flat.param.imethod = "CS"
kmo_illumination_flat.param.neighborhoodRange = 1.001
kmo_illumination_flat.param.flux = False
kmo_illumination_flat.param.pix_scale = 0.2
kmo_illumination_flat.param.suppress_extension = False
kmo_illumination_flat.param.b_samples = 2048
kmo_illumination_flat.param.b_start = -1.0
kmo_illumination_flat.param.b_end = -1.0
kmo_illumination_flat.param.cmethod = "ksigma"
kmo_illumination_flat.param.cpos_rej = 3.0
kmo_illumination_flat.param.cneg_rej = 3.0
kmo_illumination_flat.param.citer = 3
kmo_illumination_flat.param.cmax = 1
kmo_illumination_flat.param.cmin = 1

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

import cpl
kmo_illumination_flat = cpl.Recipe("kmo_illumination_flat")
[...]
res = kmo_illumination_flat( ..., param = {"imethod":"CS", "neighborhoodRange":1.001})

See also

cpl.Recipe for more information about the recipe object.

Bug reports

Please report any problems to Alex Agudo Berbel. Alternatively, you may send a report to the ESO User Support Department.