The vimos_ima_twilight_flat recipe

vimos_ima_twilight_flat

Synopsis

Twilight flat combination for imaging

Description

vimos_ima_twilight_flat – VIMOS twilight flat combine recipe.

Combine a list of twilight flat frames into a mean frame. Optionally compare the output frame to a reference twilight flat frame

The program accepts the following files in the SOF:

Tag Description FLAT_TWILIGHT A list of raw twilight flat images MASTER_BIAS A master bias frame MASTER_DARK A master dark frame REFERENCE_TWILIGHT_FLAT Optional reference twilight flat frame

If no reference twilight flat is made available, then no comparison will be done. This means there will be no output ratio image and no stats

Constructor

cpl.Recipe("vimos_ima_twilight_flat")

Create an object for the recipe vimos_ima_twilight_flat.

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

Parameters

vimos_ima_twilight_flat.param.lthr

Low rejection threshold for underexpsed images (float; default: 4000.0) [default=4000.0].

vimos_ima_twilight_flat.param.hthr

High rejection threshold for overexposed images (float; default: 60000.0) [default=60000.0].

vimos_ima_twilight_flat.param.combtype

Combination algorithm (str; default: ‘median’) [default=”median”].

vimos_ima_twilight_flat.param.scaletype

Scaling algorithm (str; default: ‘multiplicative’) [default=”multiplicative”].

vimos_ima_twilight_flat.param.xrej

True if using extra rejection cycle (bool; default: True) [default=True].

vimos_ima_twilight_flat.param.thresh

Rejection threshold in sigma above background (float; default: 5.0) [default=5.0].

vimos_ima_twilight_flat.param.ncells

Number of cells for diff image stats (int; default: 8) [default=8].

vimos_ima_twilight_flat.param.prettynames

Use pretty output file names? (bool; default: False) [default=False].

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

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

vimos_ima_twilight_flat.param.lthr = 4000.0
vimos_ima_twilight_flat.param.hthr = 60000.0
vimos_ima_twilight_flat.param.combtype = "median"
vimos_ima_twilight_flat.param.scaletype = "multiplicative"
vimos_ima_twilight_flat.param.xrej = True
vimos_ima_twilight_flat.param.thresh = 5.0
vimos_ima_twilight_flat.param.ncells = 8
vimos_ima_twilight_flat.param.prettynames = False

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

import cpl
vimos_ima_twilight_flat = cpl.Recipe("vimos_ima_twilight_flat")
[...]
res = vimos_ima_twilight_flat( ..., param = {"lthr":4000.0, "hthr":60000.0})

See also

cpl.Recipe for more information about the recipe object.

Bug reports

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