Flare Imaging

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Preparation

First, identify the time when the flare in question happened. There are many ways to do this, but a nice way is to use the RHESSI Browser and check "EOVSA Radio Data" on the upper left. Use the time you identified to find the corresponding IDB file(s) under /data1/eovsa/fits/IDB/yyyymmdd/. Then, on pipeline, it is advised to go to your working directory and copy the IDB data into your directory. Note, never, NEVER, work directly on the IDB data in the original data directory! Here I use /data1/eovsa/fits/IDB/20170711/IDB20170711201620 (2017 July 11 C flare) as an example.

Calibration

Start CASA in your working directory (it takes a minute or so to load)

casa

1. Perform polarization rotation and attenuation calibration.

idbfile='IDB20170711201620'
from eovsapy import pipeline_cal as pc
pc.udb_corr(idbfile,calibrate=True)

This will create a new IDB dataset named IDB20170711201620_1

2. Import Miriad file into CASA.

importeovsa(idbfiles='IDB20170711201620_1', doscaling=False)

Remember it is important to set doscaling=False to disable scaling cross-correlation visibilities to auto-correlation. The output is automatically named "IDB20170711201620_1.ms".

3. Perform reference phase calibration and multiband delay calibration (daily phase calibration). First, go to this page and check if reference calibrations and daily phase calibrations have already been in the database. If not, create them following the instructions on reference calibration, daily phase calibration, and total power calibration.

Note for now there is an annoying issue in CASA 5.1.0 that clean does not run after any parallelized tasks. So it would be safe to exit CASA before running calibeovsa if you set doimage=True.

calibeovsa(vis='IDB20170711201620_1.ms', caltype=['refpha','phacal'], doimage=True)

This will calibrate the input visibility, write out calibration tables, and apply the calibration. If doimage=True, a quicklook image will be produced (by integrating over the entire time).

Note both importeovsa and calibeovsa are now a CASA task. If you want to use more functionality of them and/or see more information of each parameter, you can follow the normal procedure of using a CASA task.

selfcalibration