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 Name | Requirements | Comments |
MEASURE_READNOISE | None | Calculates readnoise |
DARK_AND_BPM | None | Calculates dark current and bad pixel mask |
REDUCE_DARK | None | Stores as dark |
REDUCE_FLAT | None | Stores as a flat |
SKY_FLAT | Dark | Stores as flat, no object masking |
SKY_FLAT_MASKED | Dark | Masks any objects |
SKY_FLAT_POL_ANGLE | Dark | Stores a polarimetry flat at each WP angle |
Point Source Recipes – Non-Thermal
Recipe Name | Requirements | Comments |
BRIGHT_POINT_SOURCE | Dark; separate flat field | Background too low for self-flat |
BRIGHT_POINT_SOURCE_APHOT | Dark; separate flat field | Low background, photometry on center |
JITTER_SELF_FLAT | Dark | Creates flat from a sequence of jittered target frames |
JITTER_SELF_FLAT_APHOT | Dark | As above with photometry on center |
JITTER_SELF_FLAT_NO_MASK | Dark | As above, though quicker: use if field uncrowded |
JITTER_SELF_FLAT_BASIC | Dark | Quicker still with only registration to nearest pixel |
JITTER_SELF_FLAT_NCOLOUR | Dark | A single group using the filter iterator, produces a mosaic for each filter |
SKY_AND_JITTER | Dark; separate flat field | Sky then on-source jitter |
SKY_AND_JITTER_APHOT | Dark; separate flat field | Sky then on-source jitter with photometry |
Point Source Recipes – Thermal
Recipe Name | Requirements | Comments |
NOD_SELF_FLAT_NO_MASK | Dark | Pairs subtracted for fast sky removal, self flat |
NOD_SELF_FLAT_NO_MASK_APHOT | Dark | As above with photometry on positive and negative images of target |
Extended Source Recipes
Recipe Name | Requirement | Comments |
QUADRANT_JITTER | Dark | Jitter source between 4 quadrants of the array; good for slightly extended target where surroundings are clean for flat |
QUADRANT_JITTER_NO_MASK | Dark | As above, though quicker: Use if field uncrowded. |
QUADRANT_JITTER_BASIC | Dark | As above, though quicker still with one registration to nearest pixel |
EXTENDED_3x3 | Dark | Alternates sky/object, maps area 3×3 frames on object |
EXTENDED_3x3_BASIC | Dark | Same as above, though without masking and resampling for speed |
EXTENDED_5x5 | Dark | Alternates sky/object, maps area 5×5 frames on object |
EXTENDED_5x5_BASIC | Dark | Same as above, though without masking and resampling for speed |
NOD_SKY_FLAT_THERMAL | Dark | Alternate object and sky frames are subtracted and divided by a flat formed from the sky |
CHOP_SKY_JITTER | Dark | Alternating between object and sky, subtracts a modal sky value and is not suitable for thermal imaging |
CHOP_SKY_JITTER_BASIC | Dark | Alternating between object and sky, though without masking and resampling for speed |
Moving (Non-Sidereal) Source Recipes
Recipe Name | Requirements | Comments |
MOVING_JITTER_SELF_FLAT | Dark | Registration uses ephemeris data |
MOVING_JITTER_SELF_FLAT_BASIC | Dark | For speed on moving target (without masking and resampling) |
JITTER_SELF_FLAT_TELE | Dark | Telescope tracks moving object; uses telescope offsets to register |
Polarimetry Recipes
Recipe Name | Requirements | Comments |
SKY_FLAT_POL_ANGLE | Dark | Offset on blank sky; creates flat for each WP angle separately. |
POL_JITTER | Dark; separate “POL” flat field | Jitter E-W on source at each of 4 WP posts. |
POL_ANGLE_JITTER | Dark; separate “POL” flat field | Observes 4 WP posns. then jitters EW |
POL_EXTENDED | Dark; separate “POL” flat field | Object/Sky pairs at each of 4 WP posns. |
Miscellaneous Recipes
Recipes Name | Requirements | Comments |
QUICK_LOOK | None | Display raw data file (and covert from HDS to NDF) |
NIGHT_LOG | None | Generate an ascii log |