VLBA Station Hardware

Radio Receivers
Though extremely sophisticated, the VLBA's radio receivers perform a function quite similar to that of any radio - they convert the radio waves collected by the antenna into electrical signals that can be amplified and processed by additional electronic equipment. The VLBA radio receivers are among the most sensitive in the world. They are cooled by liquid helium refrigerators to within a few degrees of absolute zero (-273 degrees Celsius) to help receive extremely faint signals from space. The natural signals from astronomical bodies are billions of times weaker than the signals received by ordinary communications systems.

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.