Facilities > ALMA/NAASC > Data Reduction Visitors to the North American ALMA Science Center (NAASC)

Data Reduction Visitors to the North American ALMA Science Center (NAASC)

by Dong-Chan Kim last modified Aug 06, 2018


NRAO HQ, aka Stone HallData Reduction Visitors are ALMA users coming to NAASC for a week or less for expert assistance with obtaining the optimum results from their data. Funding may also be available for visits to the NRC in Canada upon request.


We expect that the majority of short-term visitors to the NAASC will come for access to NAASC computing facilities, and for expert assistance with re-processing and analyzing their ALMA data, which is central to the successful interpretation of complex interferometric data sets. To meet this need, the NAASC runs a visitor program. In some cases short-term visits may be scheduled for assistance with the technical aspects of ALMA proposals or designing scheduling blocks (SBs). Scientists carrying out archival projects may also take advantage of the visitor program.

The NAASC will provide assistance to up to three visitors from each scheduled or observed project, though funds for travel are more restricted. An experienced investigator must accompany any student who is new to radio interferometry.


Although the visitor program is available to all ALMA users, one investigator from a U.S. institution may request funds to travel to the NAASC to plan observations, or reduce data for an approved project. Reimbursement may be requested for a second investigator from a U.S. institution, provided he or she is a student. In addition, travel support to the NAASC for research on archival data analysis may be available. The reimbursement will be for the actual cost of economy airfare, up to a limit of $1000, originating from within the U.S. including its territories and Puerto Rico and on a U.S. carrier. Costs of lodging may also be reimbursed, up to $100/night. No reimbursement will be made for ground transportation or meals.

To qualify, an investigator from a U.S. institution must not be employed at a Federally Funded Research and Development Center (FFRDC) or its sponsoring agency. Exceptions are possible (e.g., investigators early in their careers); contact Tim Bastian to request an exception. The NSF maintains a master government list of FFRDCs.

NAASC Staff and Computer Support

A NAASC staff member will be assigned to be the "Contact Scientist" for the project, and will be the primary NAASC contact person for the visiting team. The Contact Scientist will answer any logistical questions prior to the visit and will spend up to 2 hours per day with the visiting team.

The NAASC provides dedicated office space and high-end computing facilities for visitors. Special needs or plans to work on a private laptop computer should be discussed with the Contact Scientist before arrival. Visitors should also discuss available methods for bringing their reduced data back home with them (external hard drive, ftp, DVD, etc.) before the visit. A copy of the data the visitor has been working on will be kept on the NAASC computers for at least a few weeks after a visit. That way, if there are post-visit questions, the Contact Scientist for the project can look directly at the data, making it much easier to understand any problems.

After a visit, visitors will be invited to submit feedback on the service received and whether the goals of the visit were met.

Number of Visitors

The NAASC visitor program is limited by the availability of office space, funds to cover visitors' travel expenses, and the time of NAASC staff to help visitors. The NAASC anticipates being able to accommodate two teams of visitors per week, with each team receiving up to 2 hours of one-on-one time with a NAASC staff member per day. A team may have up to three members, though funds for travel are restricted to 1-2 members per team, as described above.

Arranging a Visit to the NAASC

Astronomers wishing to arrange a visit to the NAASC may do so via an ALMA Helpdesk ticket to the "visits" category. A visit request ticket may be submitted at any time. A NAASC staff member, usually the Contact Scientist for the project, will contact the ticket submitter to schedule and discuss the proposed visit. The visitor program is run on a space and resource-available basis.

The NAASC will provide assistance with travel arrangements, if requested, and can make the reservations and cover the costs directly if the visitor is receiving financial aid from the NAASC. Alternatively the traveler may make their own travel arrangements, subject to the restrictions described above, and request re-imbursement. Visitors are responsible for paying for their own ground transportation and meals.

What to do Prior to a Visit

  • Familiarize yourself with CASA
  • Familiarize yourself with the basics of interferometry (e.g., see this resource)
  • You will be contacted by a NAASC staff member to help arrange your visit.
    • Flights
    • Hotel
    • Ground transportation
    • Reimbursement (if applicable)
  • Let your Contact Scientist know of any special requirements you have for reduction and analysis of your data.


Transporting Data

Visiting scientists who intend to bring all of their ALMA data home should bring a storage device with them, such as an external hard drive or a laptop with sufficient storage.  Keep in mind that ALMA data sets are often several hundred gigabytes.  Alternatively, visitors can simply bring back the data reduction script and copy the raw data from the ALMA archive to a computer at their home institute at their leisure.

Accommodations in Charlottesville

There are a number of hotel options available in Charlottesville. General information about recommended hotels can be found here.

Maps & Directions to the NAASC and NRAO in Charlottesville, Virginia


Long-Term Visitors to the NAASC


Visiting ALMA


Current NAASC Visitors