Mark 6 Data Transmission System

by VLBA SUS — last modified Dec 19, 2019 by Tony Perreault

The VLBA's data transmission system comprises the recorder units at the stations, playback units at the correlator, and the magnetic disk modules that are shipped between those units.

A transition of the VLBA to the Mark 6 recording/playback system, designed by Haystack Observatory and Conduant Corporation, is now complete at the VLBA stations and the correlator in Socorro. Current documentation on the Mark 6 system is available at Haystack's Mark 6 website.

Although Mark 6 is specified to record data at up to 16 Gbps, inputs available from the current RDBE systems limit its application to 4 Gbps.  There is, thus, substantial headroom to support recording of data from newer, higher-capacity digital signal processing units that may be developed to replace the RDBE.

The new 4-Gbps limit makes available additional observational modes within the limits of the RDBE, but the current recording media supply will support only a fraction of observing time at that higher data rate. The fraction of observing time that is expected to be available for VLBA observations is specified in each Call for Proposals for upcoming cycles.