DRP assessments

Analysis class: mangadap.proc.reductionassessments.ReductionAssessments

Reference root: $MANGA_SPECTRO_ANALYSIS/$MANGADRP_VER/$MANGADAP_VER/common

Reference file: manga-[PLATE]-[IFUDESIGN]-[DRPQA_KEY].fits.gz

Config files: $MANGADAP_DIR/python/mangadap/config/reduction_assessments

Example config: snrg.ini

# The response function used is that provided by Jim Gunn in June 2001,
# found here:
#
# http://www.sdss3.org/binaries/filter_curves.fits
#
# and parsed into text files.
[Path]
 dapsrc                 = ${MANGADAP_DIR}

[default]
 key                    = SNRG
 wave_limits
 response_function_file = ${Path:dapsrc}/data/filter_response/gunn_2001_g_response.db
 in_vacuum              = True
 covariance             = True

Important class dependencies:

  • mangadap.drpfits.DRPFits: Advanced class interface to the DRP output files that provides most of the assessments

Algorithm:

  • Ignore any pixels masked with DONOTUSE or FORESTAR bits by DRP.
  • Compute sky coordinates of each spaxel using the WCS coordinates (SPX_SKYCOO in MAPS file)
  • Use input ellipticity and position angle parameters to compute semi-major axis radii (SPX_ELLCOO in MAPS file)
  • Determine the fraction of unmasked wavelength channels for each spaxel
  • If config specifies covariance calculation, compute the covariance using the LOGRSS file at:
    • the center of the wavelength range if wavelength limits specified or,
    • the broad-band weighted center of the response function
  • Compute the (band-weighted) mean signal in each spaxel (SPX_MFLUX in MAPS file), (band-weighted) mean variance in each spaxel (SPX_MFLUX_IVAR in MAPS file), and the (band-weighted) mean S/N in each spaxel (SPX_SNR in MAPS file).