3.1.15. defineFlatStripes

Define flat field stripe locations for extraction and straylight removal.

Save fiber location info based on flat field info for stray light removal (extract=False) and for future science extraction (extract=True). Requires the findStripes and identifyStripes primitives to be run prior during recipe so necessary information exists in input extensions. Will remove previous (improperly formatted, but fast) STRIPES_ID and STRIPES_LOC extensions and replace with INDEX_FIBER and INDEX_ORDER pixel map extensions, as needed in straylight removal, and (if extract=True) a FITS savable STRIPES_ID and STRIPES_FIBERS.

For a given slit_height, this function extracts the flat field stripes, calculates a box extracted spectrum and normalizes the flat field to generate a 2D pixel map that is used in the straylight removal.

STRIPES_ID and STRIPES_FIBERS contain the by-spectral-order polynomial plate solution for each illuminated fiber that is utilized to define 2D extraction regions in science extractions.

3.1.15.1. Parameters

adinputslist of AstroData

MX flat frames. Each frame is either a DFFFD flat, an FDDDF flat, or a combined FFFFF flat.

suffixstr

Suffix to be added to output files.

slit_heightint

Half pixel height of box in each dimension to perform box extraction with.

extractbool

If True, will write STRIPES_ID in fits-acceptable format. Utilized in combined, all fiber illuminated FFFFF_flat.

3.1.15.2. Returns

list of AstroData

The input frames with the following extensions added:

  • INDEX_FIBER : 2D pixel map of fiber assignments.

  • INDEX_ORDER : 2D pixel map of echelle order assignments.

  • STRIPES_ID : (if extract=True) FITS-savable by-spectral-order polynomial plate solution for each illuminated fiber.

  • STRIPES_FIBERS : (if extract=True) companion to STRIPES_ID used to define 2D extraction regions in science extractions.

3.1.15.3. Parameter defaults and options

suffix               ''                   Filename suffix
slit_height          10                   Pixel illumination in cross-dispersion
extract              False                Save extracted Stripes?

3.1.15.4. Algorithm

Todo

add description

3.1.15.5. Issues and Limitations

Todo

add description