VIRCAM Pipeline  2.3.12
vircam_science_postprocess

Tile a set of vircam stacks.

Tile a set of vircam stacks.

Name:
vircam_science_postprocess
Purpose:
Tile a complete set of vircam stacks
Description:
The stacks from a vircam tile are combined into a single stack. A source catalogue is generated and photometric and astrometric calibration is done relative to 2MASS.
Language:
C
Parameters:
General reduction parameters:
  • nebulise (bool): If set, then the catalogues are derived from a tile that has been corrected with an unsharp mask
  • grout (bool): If set then the source catalogue will be corrected using the grout algorithm
  • minphotom (int): The minimum number of standards for photometry
  • prettynames (bool): True if we're using nice file names
  • cdssearch (bool): True if we get 2MASS standards from CDS.
  • cacheloc (string): The location of the standard star cache
  • magerrcut (float): A cut in the magnitude error for photometric standard stars

Parameters for source detection on the tile:

Parameters for nebuliser algorithm:

Input File Types:
The following list gives the file types that can appear in the SOF file. The word in bold is the DO category value.
  • JITTERED_IMAGE_SCI (required): The list of science jittered images.
  • CONFIDENCE_MAP_SCI (required): The list of science jittered confidence maps
  • OBJECT_CATALOGUE_SCI (required): The list of science source catalogues
  • PHOTCAL_TAB (required): A photometric calibration table
  • MASTER_2MASS_CATLAOGUE (required): A master 2MASS catalogue location (unless using cdssearch).
  • SCHLEGEL_MAP_NORTH (required): The Northern Schlegel dust map
  • SCHLEGEL_MAP_SOUTH (required): The Southern Schlegel dust map
Output Products:
The following list gives the output data products that are generated by this recipe. The word in bold gives the DPR CATG keyword value for each product:
  • The output mosaicked tile (TILED_IMAGE)
  • The output mosaicked tile confidence map (TILED_CONFIDENCE_MAP)
  • The extracted source catalogue for the tile (OBJECT_CATALOGUE_SCI)
Output QC Parameters:
  • SATURATION The saturation level in ADUs.
  • MEAN_SKY The mean level of the background sky over the image in ADUs.
  • SKY_NOISE The RMS of the background sky over the image in ADUs
  • IMAGE_SIZE The average size of stellar objects on the image in pixels
  • ELLIPTICITY The average ellipticity of stellar objects on the image
  • POSANG The average position angle in degrees from North towards East. NB: this value only makes sense if the ellipticity is significant
  • APERTURE_CORR The aperture correction for an aperture of radius rcore.
  • NOISE_OBJ The number of noise objects found in the image
  • MAGZPT The photometric zero point
  • MAGZERR The internal error in the photometric zero point
  • MAGNZPT The number of stars used to determine the magnitude zero point
  • MAGNCUT The number of stars cut from magnitude zero point calculation
  • SKYBRIGHT The sky brightness in mag/arcsec**2
  • LIMITING_MAG The limiting magnitude for this image for a 5 sigma detection.
  • WCS_DCRVAL1 The offset of the equatorial coordinate represented by CRVAL1 from the raw frame to the reduced one (degrees).
  • WCS_DCRVAL2 The offset of the equatorial coordinate represented by CRVAL2 from the raw frame to the reduced one (degrees).
  • WCS_DTHETA The change in the WCS coordinate system rotation from the raw to the reduced frame (degrees)
  • WCS_SCALE The scale of the pixels in the reduced frames in arcseconds per pixel
  • WCS_SHEAR The shear of the astrometric solution in the form of the difference between the rotation of the x solution and the rotation of the y solution (abs(xrot) - abs(yrot) in degrees)
  • WCS_RMS The average error in the WCS fit (arcsec)
Notes
None.
Fatal Error Conditions:
  • NULL input frameset
  • Input frameset headers incorrect meaning that RAW and CALIB frame can't be distinguished
  • No science frames in the input frameset
  • Required master calibration images and tables are missing
  • Unable to save data products
Non-Fatal Error Conditions:
  • None
Conditions Leading To Dummy Products:
  • Master calibration images either won't load or are flagged as dummy
  • The detector for the current image extension is flagged dead in all science frames
  • Various processing routines fail.
Author:
Jim Lewis, CASU
Code Reference:
vircam_science_postprocess.c