Status
SMA Data ReductionApril 2024
Known Issues
Flux calibration
There have been issues getting the flux scaling routines in CASA to work with some SMA calibrators. CASA's setjy task can fail for sources without CASA models or solar system objects with significant structure. Users should visit the sma-data-reduction GitHub repository which contains calibration scripts with work-arounds for this problem.
Polarization
The is not currently a pathway for processing SMA polarization data with CASA. Users may request the data is CASA measurement set format for the purposes of inspection, but will not be able to perform the necessary calibration steps. Nor does the current conversion with pyuvdata allow it to be used as total intensity data. Both of these issues are under development and we hope to have a solution by the second half of 2024. For help calibrating polarization data contact smarequester@cfa.harvard.edu.
Updates & Info
Tsys applicationTsys application is an option in pyuvdata. If the Tsys is applied the resulting visibilities will be scaled to produce uncalibrated values in Jy. If Tsys calibration is not requested be warned that the Tsys information has not been propagated to the measurement set and is essentially lost. To correct for the atmosphere, your only option will be to use a gain calibrator.
Shared risk data
Data between 200801 and 200119 include shared risk data where the two new chunks s5 and s6 were added. These 2 chunks will cover the bottom 4GHz of the LSB and the top 4GHz of the USB. These chunks were undergoing commissioning so the data should be carefully checked before being used for any science purposes.
Documentation
Data reduction documentation is currently being expanded. Visit the RTDC webpages and report any problems or queries to holly.thomas@cfa.harvard.edu.
