Correlation Facility Photos

These photos from 2008 show the JIVE correlation facility, a large room that is dominated by 16 data playback units (DPUs). These recover the data that were recorded at each telescope and feed these via the station unit (the box with the green and/or red lights that sits underneath each DPU) into the MkIV data processor (correlator). Also visible are some of the computing facilities which are used to control the correlation and to process the output data.

 

The following pictures are from 2004(?), when some of the DPUs were first removed and replaced by the Mark5 disc system (first picture).


 

 

These photos were taken earlier, when VLBI data was still recorded on tape.



 

The following photos are from a Mk5A fire in 2003.


 

The correlator itself, pictured below in 2010, is located in a separate room. It contains a thousand processors working in parallel and is capable of sixteen thousand billion operations per second.



 

Below left is how the correlator looked in 2004. Below right is an undated photo of the prototype correlator.


 

The Post Correlator Integrator (PCInt) pictured below is the most recent major addition to the JIVE data processor. This powerful computing and data-storage system allows the full output data rate of the correlator to be used. Previously this was not possible because the output data path was too slow and there was nowhere big enough to store the data.


The next picture shows the storage facility, previously for magnetic tapes (shown), now for disk packs. This enormous carousel, also known as the "paternoster", is so big that when the "new" building housing the correlator (and much of ASTRON) was built, it was the first thing to be installed, with the building then constructed around it. This amazing gizmo not only stores the tapes, but presents the requested disk pack by spinning to the correct tray and then pointing at the correct pack with a laser.