Model Map

Mode:

ModelMap

Usage:

Offline

Key:

MegaraModelMap

Product:

ModelMap.

Recipe:

ModelMapRecipe

Recipe input:

ModelMapRecipeInput

Recipe result:

ModelMapRecipeResult

Although for the majority of the observing modes described elsewhere in this document the MEGARA off-line pipeline will perform its own fiber spectra extraction from the 2D CCD FITS frame, there are cases where an archival master “model map” should be used instead. Note that a different “model map” should be available for each pseudo-slit and VPH combination.

Requirements

This offline observing mode will use the images obtained in the online observing mode “Trace”.

Procedure

The “User” processes an observing block obtained in the observing mode Trace. This mode includes the required actions to obtain a mapping of the profiles of the fibers. The master model map generated is used in other stages of the data processing.

Products

Trace map image sets are to be obtained both as part of the activities related to the verification of the instrument status and for processing data for scientific exploitation. Note, however, that the use of this observing mode for scientific exploitation should be limited as it could affect to the general performance of the on-line quick-look software.

This mode produces the profile information required to perform advanced extraction of the fibers. The result is stored in an object named master_model of type ModelMap.

Recipe

class megaradrp.recipes.calibration.modelmap.ModelMapRecipe(*args, **kwargs)

Provides fiber profile information from continuum flat images.

This recipe process a set of continuum flat images obtained in Trace Map mode and returns the fiber profile information required to perform advanced fiber extraction in other recipes. The recipe also returns the result of processing the input images upto dark correction.

See also

megaradrp.products.modelmap.ModelMap

description of ModelMap product

megaradrp.recipes.calibration.tracemap.TraceMapRecipe

description of TraceMap recipe

megaradrp.instrument.configs

instrument configuration

Notes

Images provided in obresult are trimmed and corrected from overscan, bad pixel mask (if master_bpm is not None), bias and dark current (if master_dark is not None). Images thus corrected are the stacked using the median.

The result of the combination is saved as an intermediate result, named ‘reduced_image.fits’. This combined image is also returned in the field reduced_image of the recipe result and will be used for fiting the profiles of the fibers.

The approximate central position of the fibers is obtained from master_traces. Then, for each 100 columns of the reduced image, a vertical cut in the image is fitted to a sum of fiber profiles, being the profile a gaussian convolved with a square.

The fits are made in parallel, being the number of processes controlled by the parameter processes, with the default value of 0 meaning to use the number of cores minus 2 if the number of cores is greater or equal to 4, one process otherwise.

After the columns are fitted, the profiles (central position and sigma) are interpolated to all columns using splines. The coefficientes of the splines are stored in the final master_traces object.

The recipe returns also the RSS obtained by applying advanced extraction to reduced_image. As an intermediate result, the recipe proceduces DS9 reg files with the position of the center of the profiles, that can be used with raw and reduced images.

class ModelMapRecipeInput(*args, **kwds)

ModelMapRecipeInput documentation.

Attributes:
debug_plotint, requirement, optional

Save intermediate tracing plots

master_biasMasterBias, requirement

Master BIAS image

master_bpmMasterBPM, requirement, optional

Master Bad Pixel Mask

master_darkMasterDark, requirement, optional

Master DARK image

master_slitflatMasterSlitFlat, requirement, optional

Master slit flat calibration

master_tracesTraceMap, requirement

Trace information of the Apertures

obresultObservationResultType, requirement

Observation Result

processesint, requirement, optional

Number of processes used for fitting

class ModelMapRecipeResult(*args, **kwds)

ModelMapRecipeResult documentation.

Attributes:
master_modelModelMap, product
reduced_imageProcessedImage, product
reduced_rssProcessedRSS, product
RecipeInput

alias of ModelMapRecipeInput

RecipeResult

alias of ModelMapRecipeResult