Tape Recorders, Station Computer
The signals from the receivers are amplified, digitized and organized
into a standardized format then recorded on ultrafast recorders. Tapes
containing the recorded data are then sent from the VLBA stations to the
correlator at the Array Operations Center (AOC) in Socorro, New Mexico.
The station computer at each site controls all of the station's equipment
and makes sure that everything works together properly. Each site computer
also communicates over the Internet with a master computer system at the
AOC so that the operators can monitor the condition at each station
simultaneously.
Atomic Clock (Hydrogen Maser)
For accuracy, each station uses this device to synchronize its clocks.
By utilizing a natural resonance of hydrogen atoms as a standard, the stations
are able to maintain a timekeeping accuracy within one second in a million
years. This degree of accuracy is necessary to allow the correlator to
combine each station's data into a single image.
Weather Station
Because each site is operated remotely from the AOC, it is necessary
for the operators to be aware of the meteorological conditions that may
affect the quality of data obtained during an observation or that may affect
the safety of the equipment. Each station continually sends information
on the air temperature, dew point, wind speed, wind direction, barometric
pressure and precipitation to the master computer system at the AOC.