Facilities > ALMA/NAASC > Data Processing

Data Processing

Data Products and Data Processing Visits

After a project has been observed, it will be processed by ALMA staff, who will conduct “quality assurance” on the data products to establish whether they have reached the requested sensitivity (in a “best efforts” sense; as described in the Cycle 1 Call for Proposals). Once the data products have passed quality assurance, they will be transferred to the archive at the NAASC, and the PI will receive an email notification with instructions on how to obtain the data. It is anticipated that the data products will consist of calibrated visibilities, calibration and flagging tables, data reduction scripts, and a representative set of reference images.

The “Observing teams should anticipate the need to invest their own time and expertise to assure the quality of the provided data products and to re-reduce the raw data if the quality of the former were not satisfactory. This may include the need to visit the relevant ARC or ARC node to get help and to assist with quality assurance and potential data re-reduction.” Visits to support data reprocessing and analysis can be arranged to any of NRAO’s U.S. facilities (the NAASC at NRAO Headquarters in Charlottesville, VA; the Array Operation Center in Socorro NM; or Greenbank Science Operations in Greenbank WV), or to NRC-HIA’s facility in Victoria, BC, Canada.  It would be most advantageous to visit the facility where the Contact Scientist for a particular project is located, and during a time when (s)he is available. To request such a visit, the investigator should submit a ticket to the “Face-to-face visits” department of the helpdesk.

ALMA Cycle 1 Data Processing Workshop

In addition to offering the possibility of visits for one-on-one assistance, the NAASC will host a 2-day data processing workshop in Charlottesville on Feb 28 - Mar 1, 2013.  Further information will be available soon.

ALMA Calibration and Imaging Tutorials

Calibration and imaging of ALMA data is done via the Common Astronomy Software Applications package, CASA. CASA can be obtained at this downloads page. For self-training purposes, detailed examples of calibration and imaging of ALMA Science Verification data are documented in “CASAguides” available at CASAguides.

Hardware Recommendations for ALMA Data Processing

ALMA will generate large datasets (from 10s to 100s of GB) that cannot be effectively processed on a laptop. A list of hardware recommendations for ALMA data processing is available on the "Data Processing" page of the ALMA Science Portal".