UIST – Imaging: Data Reduction Recipes

UIST – Imaging: Data Reduction Recipes

The following tables describe the UIST imaging ORACDR recipes; click on the recipe name for more information. The Requirements listed below are frames that should be obtained prior to use of the recipe, although data can always be re-reduced when the appropriate frames have been taken. Darks must have the same integration time as the target frames, and flats must be obtained through the same filters.

Calibration Recipes

Recipe NameRequirementsComments
MEASURE_READNOISENoneCalculates readnoise
DARK_AND_BPMNoneCalculates dark current and bad pixel mask
REDUCE_DARKNoneStores as dark
REDUCE_FLATNoneStores as a flat
SKY_FLATDarkStores as flat, no object masking
SKY_FLAT_MASKEDDarkMasks any objects
SKY_FLAT_POL_ANGLEDarkStores a polarimetry flat at each WP angle

Point Source Recipes – Non-Thermal

Recipe NameRequirementsComments
BRIGHT_POINT_SOURCEDark; separate flat fieldBackground too low for self-flat
BRIGHT_POINT_SOURCE_APHOTDark; separate flat fieldLow background, photometry on center
JITTER_SELF_FLATDarkCreates flat from a sequence of jittered target frames
JITTER_SELF_FLAT_APHOTDarkAs above with photometry on center
JITTER_SELF_FLAT_NO_MASKDarkAs above, though quicker: use if field uncrowded
JITTER_SELF_FLAT_BASICDarkQuicker still with only registration to nearest pixel
JITTER_SELF_FLAT_NCOLOURDarkA single group using the filter iterator, produces a mosaic for each filter
SKY_AND_JITTERDark; separate flat fieldSky then on-source jitter
SKY_AND_JITTER_APHOTDark; separate flat fieldSky then on-source jitter with photometry

Point Source Recipes – Thermal

Recipe NameRequirementsComments
NOD_SELF_FLAT_NO_MASKDarkPairs subtracted for fast sky removal, self flat
NOD_SELF_FLAT_NO_MASK_APHOTDarkAs above with photometry on positive and negative images of target

Extended Source Recipes

Recipe NameRequirementComments
QUADRANT_JITTERDarkJitter source between 4 quadrants of the array; good for slightly extended target where surroundings are clean for flat
QUADRANT_JITTER_NO_MASKDarkAs above, though quicker: Use if field uncrowded.
QUADRANT_JITTER_BASICDarkAs above, though quicker still with one registration to nearest pixel
EXTENDED_3x3DarkAlternates sky/object, maps area 3×3 frames on object
EXTENDED_3x3_BASICDarkSame as above, though without masking and resampling for speed
EXTENDED_5x5DarkAlternates sky/object, maps area 5×5 frames on object
EXTENDED_5x5_BASICDarkSame as above, though without masking and resampling for speed
NOD_SKY_FLAT_THERMALDarkAlternate object and sky frames are subtracted and divided by a flat formed from the sky
CHOP_SKY_JITTERDarkAlternating between object and sky, subtracts a modal sky value and is not suitable for thermal imaging
CHOP_SKY_JITTER_BASICDarkAlternating between object and sky, though without masking and resampling for speed

Moving (Non-Sidereal) Source Recipes

Recipe NameRequirementsComments
MOVING_JITTER_SELF_FLATDarkRegistration uses ephemeris data
MOVING_JITTER_SELF_FLAT_BASICDarkFor speed on moving target (without masking and resampling)
JITTER_SELF_FLAT_TELEDarkTelescope tracks moving object; uses telescope offsets to register

Polarimetry Recipes

Recipe NameRequirementsComments
SKY_FLAT_POL_ANGLEDarkOffset on blank sky; creates flat for each WP angle separately.
POL_JITTERDark; separate “POL” flat fieldJitter E-W on source at each of 4 WP posts.
POL_ANGLE_JITTERDark; separate “POL” flat fieldObserves 4 WP posns. then jitters EW
POL_EXTENDEDDark; separate “POL” flat fieldObject/Sky pairs at each of 4 WP posns.

Miscellaneous Recipes

Recipes NameRequirementsComments
QUICK_LOOKNoneDisplay raw data file (and covert from HDS to NDF)
NIGHT_LOGNoneGenerate an ascii log