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The vmimpreimaging recipe

vmimpreimaging

Synopsis

Reduce a preimaging science exposure.

Description

This recipe is used to apply basic reduction steps to the imaging observation that is preliminary to a MOS observation of the same field. No source detection is attempted on the image. The image WCS, together with the component describing the instrument optical distortions, is converted into the convention followed by VMMPS (the VIMOS mask preparation software). This set of coefficients, the so-called CO-matrix used by the SAO WCSTools package, is written to the header of the reduced image.

Input files

DO category:              Type:       Explanation:         Required:
IMG_PREIMAGING            Raw         Preimaging exposure     Y
MASTER_BIAS               Calib       Master bias             Y
IMG_MASTER_SKY_FLAT       Calib       Master sky flat         Y
PHOT_COEFF_TABLE          Calib       Photometric table       .

CCD_TABLE                 Calib       Bad pixel table         .

Output files

DO category:              Data type:  Explanation:
IMG_SCIENCE_REDUCED       FITS image  Reduced preimaging exposure

If a photometric table is specified, the magnitude zeropoint, the atmospheric extinction coefficient, and the colour term are copied from the photometric table to the header of the reduced image. A CCD table must be specified in input only if a bad pixel cleaning is requested.

For more details, please refer to the VIMOS Pipeline User’s Guide.

Constructor

cpl.Recipe("vmimpreimaging")

Create an object for the recipe vmimpreimaging.

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

Parameters

vmimpreimaging.param.BiasMethod

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

vmimpreimaging.param.CleanBadPixel

Bad pixel correction on reduced science image. (bool; default: False) [default=False].

vmimpreimaging.param.CleanCosmic

Cosmic ray removal from the input science image. (bool; default: True) [default=True].

vmimpreimaging.param.CosmicsThreshold

Threshold for cosmic ray candidate selection. (float; default: 4.0) [default=4.0].

vmimpreimaging.param.CosmicsRatio

Ratio for discrimination of objects and cosmics. (float; default: 2.0) [default=2.0].

vmimpreimaging.param.TemperatureCheck

Check beam temperature when updating the world coordinate system. (bool; default: True) [default=True].

vmimpreimaging.param.TemperatureTolerance

Maximum allowed difference between beam and ambient temperature. (float; default: 3.0) [default=3.0].

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

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

vmimpreimaging.param.BiasMethod = "Zmaster"
vmimpreimaging.param.CleanBadPixel = False
vmimpreimaging.param.CleanCosmic = True
vmimpreimaging.param.CosmicsThreshold = 4.0
vmimpreimaging.param.CosmicsRatio = 2.0
vmimpreimaging.param.TemperatureCheck = True
vmimpreimaging.param.TemperatureTolerance = 3.0

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

import cpl
vmimpreimaging = cpl.Recipe("vmimpreimaging")
[...]
res = vmimpreimaging( ..., param = {"BiasMethod":"Zmaster", "CleanBadPixel":False})

See also

cpl.Recipe for more information about the recipe object.

Bug reports

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