UKIRT
Show document only
UKIRT Home
Contact Info
OMP
UKIRT Staff wiki
Weather
Web Cameras
____________________

Survey Observing
Other Observing
Observing Tool Manual
Schedule
Applying For Time
Get UKIDSS Data
Get non-UKIDSS Data
Data Reduction
Acknowledge Us
Telescope
WFCAM
Cassegrain
Technical Reference
UKIRT Publications
Graphical Weather Server
EAO Safety Manual
UKIRT Waiver Form
TSS Priority Page
UKIRT Current status
ORAC-DR ONLINE DATA REDUCTION
UKIRT


Introduction

The summit data reduction uses the orac-dr pipeline, calling the Starlink algorithm set. The pipeline is invoked by first setting up environment variables:

oracdr_uist

and then running the actual pipeline:

oracdr -loop flag

(for WFCAM there are four pipelines, and you should see the specific instructions on the runup page). Note that oracdr_<instrument> needs to be entered only once - it does nothing but set up the environment. As a corollary, it can be entered at any time in an xterm to find out what data directories are being used.



Arguments

ORAC-DR takes only one command-line argument - the data reduction recipe to be applied. If you give no arguments, the pipeline will get the recipe specification from the FITS headers (and this is the normal mode of operation). If a recipe name (e.g. QUICK_LOOK) is given on the command line, then all frames processed by the pipeline will be processed using that recipe, whether or not it makes sense.



Options

All ORAC-DR behaviour is controlled by the option switches. It is via command line switches that you (for example) control the range of file numbers to be reduced, force the system to use a particular calibration file when reducing (e.g. to try a different flat exposure). there is a long list of options which can be listed by typing

oracdr -h

Here we list only the most common ones.

Windows and logging control

    -nodisplay

Do not launch the display system. No data will be displayed and GWM, GAIA etc. windows will not be launched.

    -log s

Log to terminal screen (standard out)

    -log f

Log to a file. The logfile is called ".oracdr_NNNN.log" where NNNNis the current process ID. It is written to $ORAC_DATA_OUT and is a hidden file.

    -log x

Log to an Xwindow. Has the advantage that warnings and errors are written to different, independently scrollable windows. The three log options can be combined. The default is "-log sx"

To run ORAC-DR using output only within the xterm that you used to invoke it in, use "-nodisplay -log s". This is the fastest way to run the pipeline if you are not interested in visually inspecting the data as it is being reduced.



Observations

    -from

Number of first observation.

    -to

Number of last observation

    -list

Comma separated list of observation *numbers*. Colons indicate a range. For example, `1,2,4:6,10' means 1,2,4,5,6,10.



Calibration options

    -calib

Used to specify calibration overrides. Accepts comma separated key=value pairs.
(e.g. `"-cal dark=file1"' or `"-cal dark=file1,bias=file2"'). The allowed options    depends on the instrument that is in use.



Looping options

The "-loop" option specifies the type of data detection loop. Allowed  values are `list', `inf', `wait', `flag' or 'file'. In almost all cases  of offline use, `inf' is most appropriate.

    -loop flag

Waits for completion files to appear (flags) before processing the data. Data is reduced and the pipeline waits for more data by checking the presence of a flag. This is how the normal summit pipeline should be run.

If you wish to start a pipeline from a given point and carry on as new data arrive, then use something like this:

oracdr -from 750 -loop flag




Examples

oracdr -loop flag
Starts a pipeline for whichever instrument was indicated by a previous oracdr_<instrument> command. Commences from the first data file of the night (file 1) and continues reducing data until manually exited. If a frame number is reached for which a data file does not yet exist, the pipeline will wait for that file (as indicated by the presence in the raw data directory of a ".ok" flag file)

oracdr -from 150 -to 154 -nodisplay Reduces frames 150 to 154 with the default recipe given in their FITS headers. Does not display the results.
oracdr -from 20 -to 105 REDUCE_DARK
Reduces frames 20 to 105 with a recipe designed for dark frames. If frames 20 to 105 are not in fact darks, this command would be ill-advised.

oracdr -from 20 -to 44 -cal dark=dark_15
Reduces frames 20 to 44 with the default FITS header recipe, using a different dark frame than would otherwise have been used (at the summit the most recent dark is the default; in this example that frame has been found to be bad and the affected range of frames are being re-reduced with a better dark).

oracdr -from 504 -loop flag JITTER_SELF_FLAT

Reduces all frames starting with number 504, using the recipe JITTER_SELF_FLAT; continuing on after all current data have been reduced by looking for the next flag file. Note that if subsequent frames don't match the SELF_FLAT recipe then this command will have negative consequences when those data are encountered.








Contact: Tom Kerr. Updated: Wed May 17 16:29:11 HST 2006

Return to top ^