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.
