The correlator is a vital component of a radio interferometer. This piece of equipment (or more recently, software) compares the signals from pairs of telescopes, generating the data which is later used to make an image. The correlation has the added benefit of reducing noise (which is generally uncorrelated between telescopes).
Bob Campell of the Joint Institute for VLBI in Europe (JIVE) gave the summer students a tour of the JIVE correlator. Follow the link below to see the pictures and descriptions of what’s in each picture. Some of the descriptions give a bit of information about how a correlator works, but I hope to provide a more complete picture in the next mini-article about my research.