Known Issues for the VLA Pipeline in CASA 4.5.3

About this Page

This page describe issues affecting the CASA Integrated Pipeline in CASA 4.5.3 (and likely 4.5.2, 4.5.1, and 4.5.0). These issues are known to either cause the pipeline to fail mid-process, causing the scripts to exit to the CASA prompt or the unexpected exiting of CASA itself, or to cause problems for calibration quality. These failures may result in little or no calibration and potentially corruption of the MS in some cases.

Last update: 2017-05-19.

 

Testdelay.k does not exist

The symptom is the pipeline fails to complete and the last line in the casa log file is:

INFO    gaincal::::casa Exiting script: Table testdelay.k does not exist

This may be caused by the pipeline finding no unflagged data on the delay calibrator, causing all subsequent calibration steps to fail. You may still be able to calibrate these data by hand or with the pipeline by selecting a different field as the delay calibrator.

 

Integrated Pipeline Restoration: Flagging failure in CASA 4.5.3

Due to an bug in hif_restoredata, CASA will give a SEVERE alert about a data shape mismatch between the final flag version and the MS created during the restore process, causing a failure to apply the final flag version saved. This came about because the 4.5.3 version of the pipeline restore script uses ocorrmode='ca', and the initial MS created by the pipeline uses ocorrmode='co'. These two options create a dataset with different row numbers and causes the error when trying to apply the final flag version. The solution is to create the MS again using hifv_importdata before running the restore script, and then editing casa_piperestorescript.py to reference the MS instead of the SDM-BDF.  This issue was fixed in CASA 4.7.x pipeline releases. Detailed instructions are below.

If you are using CASA 4.5.3 to restore data originally pipeline processed in CASA 4.5.3, you will need all the standard pipeline products and the SDM-BDF, just as you would expect from the restore instructions online, but the procedure is different.

Untar the pipeline product directory, typically named something like project-code_YYYY_MM_DD_THH_MM_SS.SSS, with YYYY_MM_DD being the date of observation, and the THH_MM_SS.SSS being a unique time stamp of when the pipeline was originally run.

Next, cd to this directory, and you should find a "products" directory. First make two new directories named exactly as follows

mkdir rawdata working

Now cd to this "rawdata" directory and move your SDM-BDF into "rawdata". You will now start CASA 4.5.3 with the pipeline from this driectory.

/path/to/your/4.5.3/installation/casa --pipeline  

or, if you are using a computer at thew New Mexico Array Science Center (NMASC), type

casa-pipe -r 4.5.3-el6

You will now run two CASA pipeline tasks: one to initialize the pipeline environment and the other to create a MS with ocorrmode='co'. The initialization should complete  very quickly, but the MS creation will take some time (especially for large datasets)

# in CASA
h_init()

# once the terminal returns, try:
hifv_importdata(vis=['mySDM'], session=['session_1'])

Here, "mySDM" is the name of your SDM-BDF. Once the MS has been created, exit CASA and leave this MS in the "rawdata" directory. Next, cd to "working".

cd ../working

Move the casa_piperestorescript.py file from "products" to "working".

mv ../products/casa_piperestorescript.py .

Now, you will need to edit this file to change the following line:

hif_restoredata(vis=['mySDM'], session=['session_1'])

to

hif_restoredata(vis=['mySDM.ms'], session=['session_1'],bdfflags=False)

Note that we changed the SDM name to a MS name, mySDM.ms. We also added bdfflags=False to remove another warning that would have come up during restore: though this shouldn't affect the functionality of the restore script, it produces a cleaner log file.

Now, from the working directory, start CASA 4.5.3 with the pipeline again.

/path/to/your/4.5.3/installation/casa --pipeline  

or, if you are using a computer at thew New Mexico Array Science Center (NMASC), type

casa-pipe -r 4.5.3-el6

Finally, we can execute the restore script to automatically recreate the pipeline calibrated MS:

execfile('casa_piperestorescript.py')

 

Issues not covered here

If you are experiencing issues running the pipeline that cause a failure to complete or if you have questions about the pipeline, please contact us via the Pipeline Department of the NRAO Helpdesk.

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