Observation Preparation & Execution

Users allocated VLBA observing time, either on fixed dates or on a dynamically-scheduled basis, will be sent instructions for preparing observing schedules.  Approximately 65% of all VLBA observations are scheduled dynamically, based on array and weather conditions predicted 1-2 days in advance.  Most VLBA observations are scheduled using the NRAO program SCHED (Walker 2011).  Help with preparing VLBA observations is available through the NRAO Helpdesk.


Each VLBA program is run remotely from the SOC by VLBA operations.  No observing assistance by a VLBA user is expected, although VLBA operations should be able to reach the observer by telephone during the program.  As the program progresses, the array operator monitors the status of the antennas and the station data path, mainly using a compact yet comprehensive display program.  Various logging, calibration, and flagging data are automatically recorded by the monitor and control system running on the station computer at each VLBA site.  If necessary, the array operator can request local assistance from a site technician at each VLBA station.  Recorded media are automatically shipped from each VLBA station to the correlator specified by the observer.

Connect with NRAO

The National Radio Astronomy Observatory and Green Bank Observatory are facilities of the U.S. National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

Founded in 1956, the NRAO provides state-of-the-art radio telescope facilities for use by the international scientific community. NRAO telescopes are open to all astronomers regardless of institutional or national affiliation. Observing time on NRAO telescopes is available on a competitive basis to qualified scientists after evaluation of research proposals on the basis of scientific merit, the capability of the instruments to do the work, and the availability of the telescope during the requested time. NRAO also provides both formal and informal programs in education and public outreach for teachers, students, the general public, and the media.

The National Science Foundation (NSF) is an independent federal agency created by Congress in 1950 "to promote the progress of science; to advance the national health, prosperity, and welfare; to secure the national defense..."

AUI collaborates with the scientific community and research sponsors to plan, build, and operate cutting-edge facilities. We cultivate excellence, deliver value, enhance education, and engage the public.