LBCgo.lbcproc

Functions

check_external_dependencies()

Check if required external tools are available.

go_overscan(image_collection[, lbc_chips, ...])

Remove overscan and trim LBC object images.

make_bias(image_collection[, bias_filename, ...])

Create a master bias frame from a collection of zero frames.

go_bias(image_collection[, bias_file, ...])

Apply a master bias frame to multi-extension FITS object data.

make_flatfield(image_collection[, filter_name, ...])

Create a master sky flat field for a single filter.

go_flatfield(image_collection[, flat_file, ...])

Apply master flat fields to multi-extension FITS object data.

go_cleancosmic(ccd[, mbox, rbox, gbox, sigclip, ...])

make_targetdirectories(image_collection[, ...])

Organise flat-fielded files into per-target and per-filter subdirectories.

go_extractchips(filter_directories[, lbc_chips, ...])

Split multi-extension flat-fielded files into single-chip FITS files.

go_scrub()

lbcgo([raw_directory, image_directory, lbc_chips, ...])

Process a directory of LBC (Large Binocular Camera) data through the complete reduction pipeline.

Module Contents

LBCgo.lbcproc.check_external_dependencies()

Check if required external tools are available.

LBCgo.lbcproc.go_overscan(image_collection, lbc_chips=True, objects_only=True, image_directory='./', raw_directory='./raw/', verbose=True, return_files=True)

Remove overscan and trim LBC object images.

Fits a 4th-order polynomial to each chip’s overscan strip (BIASSEC), subtracts it, then trims to the science region (TRIMSEC). Also removes LBC header keywords that confuse downstream astrometric tools (BIASSEC, TRIMSEC, DATASEC, ROTANGLE, PARANGLE, and all duplicate keywords ending in A).

By default only processes frames with IMAGETYP=object; calibration frames are handled internally by make_bias() and make_flatfield().

Parameters:

  • image_collection (ccdproc.ImageFileCollection) – Collection of raw LBC FITS files.

  • lbc_chips (bool or list of int, optional) – Chips to process. If True, processes all 4 chips. Default: True

  • objects_only (bool, optional) – If True, restrict to IMAGETYP=object frames. Default: True

  • image_directory (str, optional) – Output directory for overscan-corrected files. Default: ‘./’

  • raw_directory (str, optional) – Directory containing raw input files. Default: ‘./raw/’

  • verbose (bool, optional) – Print progress messages. Default: True

  • return_files (bool, optional) – Return a list of output filenames. Default: True

Returns:

Paths to overscan-corrected, trimmed FITS files (*_over.fits), or None if return_files=False.

Return type:

list of str or None

LBCgo.lbcproc.make_bias(image_collection, bias_filename=None, lbc_chips=True, image_directory='./', raw_directory='./raw/', verbose=True)

Create a master bias frame from a collection of zero frames.

Overscan-subtracts and trims each bias frame, then median-combines with 3-sigma clipping. The result is written as a multi-extension FITS file (one extension per chip). The number of combined frames is recorded in each chip header as NCOMBINE.

Parameters:

  • image_collection (ccdproc.ImageFileCollection) – Collection containing raw bias frames (IMAGETYP=zero).

  • bias_filename (str or None, optional) – Output filename for the master bias. Default: 'zero.fits'

  • lbc_chips (bool or list of int, optional) – Chips to process. If True, processes all 4 chips. Default: True

  • image_directory (str, optional) – Output directory for the master bias. Default: ‘./’

  • raw_directory (str, optional) – Directory containing raw bias frames. Default: ‘./raw/’

  • verbose (bool, optional) – Print progress messages. Default: True

LBCgo.lbcproc.go_bias(image_collection, bias_file=None, image_directory='./', input_directory='./', bias_directory='./', lbc_chips=True, verbose=True, return_files=False)

Apply a master bias frame to multi-extension FITS object data.

Parameters:

  • image_collection (ccdproc.ImageFileCollection or list of str) – Collection or list of filenames for the overscan-corrected object frames.

  • bias_file (str or None, optional) – Filename of the master bias. Default: 'zero.fits'

  • image_directory (str, optional) – Output directory for bias-subtracted files. Default: ‘./’

  • input_directory (str, optional) – Directory containing the input object frames. Default: ‘./’

  • bias_directory (str, optional) – Directory containing the master bias file. Default: ‘./’

  • lbc_chips (bool or list of int, optional) – Chips to process. If True, processes all 4 chips. Default: True

  • verbose (bool, optional) – Print progress messages. Default: True

  • return_files (bool, optional) – Return a list of output filenames. Default: False

Returns:

Paths to bias-subtracted FITS files (*_zero.fits), or None if return_files=False.

Return type:

list of str or None

LBCgo.lbcproc.make_flatfield(image_collection, filter_name=None, lbc_chips=True, image_directory='./', raw_directory='./raw/', cosmiccorrect=False, verbose=True)

Create a master sky flat field for a single filter.

Overscan-subtracts and trims each sky flat (IMAGETYP=flat, OBJECT=SkyFlat), rejects frames with mean counts above 55,000 ADU as saturated, normalises the remaining frames to a common level, and median-combines with 3-sigma clipping. The number of combined frames is stored as NCOMBINE in the primary header.

Parameters:

  • image_collection (ccdproc.ImageFileCollection) – Collection containing raw sky flat frames.

  • filter_name (str or None, optional) – Filter to process. If None, uses the first filter found in the collection summary. Default: None

  • lbc_chips (bool or list of int, optional) – Chips to process. If True, processes all 4 chips. Default: True

  • image_directory (str, optional) – Output directory for the master flat. Default: ‘./’

  • raw_directory (str, optional) – Directory containing raw flat frames. Default: ‘./raw/’

  • cosmiccorrect (bool, optional) – Apply cosmic-ray cleaning to individual flats before combining. Default: False

  • verbose (bool, optional) – Print progress messages. Default: True

Returns:

Writes flat.<filter_name>.fits to image_directory. Returns None if no usable flat frames are found.

Return type:

None

LBCgo.lbcproc.go_flatfield(image_collection, flat_file=None, filter_names=None, image_directory='./', input_directory='./', flat_directory='./', lbc_chips=True, cosmiccorrect=True, verbose=True, return_files=False)

Apply master flat fields to multi-extension FITS object data.

Loops over filters, reads the corresponding master flat, and divides each object frame by it. Pre-flat-fielded files are moved to a data/ subdirectory. Output files carry the _flat.fits suffix.

Parameters:

  • image_collection (ccdproc.ImageFileCollection) – Collection of bias-corrected (or overscan-only) object frames.

  • flat_file (str or None, optional) – Override flat filename. If None, expects flat.<filter>.fits in flat_directory. Default: None

  • filter_names (list of str or None, optional) – Filters to process. If None, all filters in the collection are used. Default: None

  • image_directory (str, optional) – Output directory for flat-fielded files. Default: ‘./’

  • input_directory (str, optional) – Directory containing input object frames. Default: ‘./’

  • flat_directory (str, optional) – Directory containing master flat files. Default: ‘./’

  • lbc_chips (bool or list of int, optional) – Chips to process. If True, processes all 4 chips. Default: True

  • cosmiccorrect (bool, optional) – Apply cosmic-ray cleaning before flat fielding. Default: True

  • verbose (bool, optional) – Print progress messages. Default: True

  • return_files (bool, optional) – Return a list of output filenames. Default: False

Returns:

Paths to flat-fielded FITS files (*_flat.fits), or None if return_files=False.

Return type:

list of str or None

LBCgo.lbcproc.go_cleancosmic(ccd, mbox=15, rbox=15, gbox=11, sigclip=5, cleantype='medmask', cosmic_method='lacosmic')
LBCgo.lbcproc.make_targetdirectories(image_collection, image_directory='./', object_names=None, verbose=True)

Organise flat-fielded files into per-target and per-filter subdirectories.

Creates <image_directory><object>/ and <image_directory><object>/<filter>/ subdirectories and moves files into them. Spaces in object names are stripped (NGC 891 → NGC891). Existing directories are silently reused.

Parameters:

  • image_collection (ccdproc.ImageFileCollection) – Collection of flat-fielded object frames to organise.

  • image_directory (str, optional) – Root output directory under which target subdirectories are created. Default: ‘./’

  • object_names (list of str or None, optional) – Restrict processing to these object names. If None, all unique OBJECT values in the collection are used. Default: None

  • verbose (bool, optional) – Print progress messages. Default: True

Returns:

  • object_directories (list of str) – Paths to the per-target directories that were created or reused.

  • filter_directories (list of str) – Paths to the per-filter subdirectories within each target directory.

LBCgo.lbcproc.go_extractchips(filter_directories, lbc_chips=True, verbose=True, return_files=False)

Split multi-extension flat-fielded files into single-chip FITS files.

For each *_flat.fits file found in the supplied filter directories, writes one output file per chip named <base>_<chip>.fits, each containing a single image extension. The original multi-extension file is moved to a data/ subdirectory. Output files are the direct inputs to the astrometric registration step.

Parameters:

  • filter_directories (str or list of str) – Directory path(s) containing *_flat.fits multi-extension files.

  • lbc_chips (bool or list of int, optional) – Chips to extract. If True, extracts all 4 chips. Default: True

  • verbose (bool, optional) – Print progress messages. Default: True

  • return_files (bool, optional) – Return a list of output filenames. Default: False

Returns:

Paths to per-chip FITS files (e.g. *_1.fits … *_4.fits), or None if return_files=False.

Return type:

list of str or None

LBCgo.lbcproc.go_scrub()
LBCgo.lbcproc.lbcgo(raw_directory='./raw/', image_directory='./', lbc_chips=True, lbcr=True, lbcb=True, filter_names=None, bias_proc=False, do_astrometry=True, astrometric_catalog='GAIA-DR3', scamp_iterations=3, verbose=True, clean=True)

Process a directory of LBC (Large Binocular Camera) data through the complete reduction pipeline.

This function performs comprehensive data reduction for LBT LBC observations, including overscan subtraction, flat fielding, cosmic ray removal, chip extraction, astrometric calibration, and final image combination. The pipeline processes multi-extension FITS files from both LBC-Blue and LBC-Red cameras.

Detailed Processing Steps: 1. Collect and filter raw image files by camera and filter 2. Create master bias frames (optional) 3. Create master flat field frames per filter 4. Remove overscan regions and trim images 5. Apply bias correction (optional) 6. Apply flat field correction 7. Organize data by target and filter into subdirectories 8. Extract individual CCD chips for astrometric processing 9. Perform astrometric calibration using SExtractor/SCAMP (optional) 10. Co-add registered images using SWARP (optional)

Parameters:

  • raw_directory (str, optional) – Path to directory containing raw LBC FITS files. Files should follow the naming convention ‘lbc[br].YYYYMMDD.NNNNNN.fits’. Default: ‘./raw/’

  • image_directory (str, optional) – Output directory for processed images and intermediate files. Default: ‘./’

  • lbc_chips (bool or list, optional) – CCD chips to process. If True, processes all 4 chips [1,2,3,4]. Can specify subset as list (e.g., [1,3]). Default: True

  • lbcr (bool, optional) – Process LBC-Red camera data. Default: True

  • lbcb (bool, optional) – Process LBC-Blue camera data. Default: True

  • filter_names (list or None, optional) – List of filter names to process (e.g., [‘g-SLOAN’, ‘r-SLOAN’]). If None, processes all filters found in data. Default: None

  • bias_proc (bool, optional) – Apply bias frame correction. Requires bias frames in raw data. Default: False

  • do_astrometry (bool, optional) – Perform astrometric calibration and image registration using SExtractor, SCAMP, and SWARP. Requires external tools to be installed. Default: True

  • astrometric_catalog (str, optional) – Astrometric reference catalog to use for SCAMP calibration. Common options include ‘GAIA-DR3’, ‘SDSS-R12’, ‘2MASS’, etc. Default: ‘GAIA-DR3’

  • scamp_iterations (int, optional) – Number of SCAMP iterations for astrometric solution refinement. Minimum of 2 iterations recommended. Default: 3

  • verbose (bool, optional) – Print detailed processing information and progress. Default: True

  • clean (bool, optional) – Clean up intermediate files after processing. If True, removes intermediate files and diagnostic outputs. If False, preserves catalog files in ‘cat/’ directory for inspection. Default: True

Returns:

Function performs file operations and creates output images in specified directories. Final products include flat-fielded individual chip images and (if do_astrometry=True) astrometrically-calibrated combined images.

Return type:

None

Notes

  • Raw files are expected to be multi-extension FITS with 4 CCD extensions

  • SkyFlatTest images are automatically excluded from processing

  • External dependencies (SExtractor, SCAMP, SWARP) are required if do_astrometry=True

  • For nights with V-band observations from both cameras, run separately with lbcr=False then lbcb=False to avoid inappropriate co-addition

  • Processing creates subdirectories organized by target name and filter

  • Intermediate files are moved to a ‘data/’ subdirectory during processing

Examples

Basic processing with astrometry: >>> lbcgo()

Process only g-band data from LBC-Blue: >>> lbcgo(lbcb=True, lbcr=False, filter_names=[‘g-SLOAN’])

Process without astrometric calibration: >>> lbcgo(do_astrometry=False)

Custom directories and bias correction: >>> lbcgo(raw_directory=’/data/lbc/raw/’, … image_directory=’/data/lbc/reduced/’, … bias_proc=True)