Very Long Baseline Interferometry (VLBI) at Arecibo

Arecibo presently supports VLBI for up to a maximum of 4% of its astronomy observing time. A hydrogen maser frequency standard is available for VLBI, this being a unit from Symmetricon Inc., (Model No. MHM2010.) For information on this unit see:
http://update.symmetricom.com/media/files/downloads/product-datasheets/DS_MHM_2010_ActiveHydrogenMaser_110512a.pdf.
The maser also serves as the Observatory master clock.

Arecibo is equipped with a VLBA4 Data-Acquisition Rack and Mark-5A, plus an RDBE digital backend and Mark-5C, VLBI recording systems. These are compatible with the HSA, EVN and Global networks, plus operations with the RadioAstron 10-m diameter orbital VLBI dish. The 305-m telescope is available for scheduling with any of these. Any proposer wishing to include the 305-m telecope in their VLBI observations should submit a proposal to the HSA, EVN or Global networks as usual, rather than to Arecibo. All proposals should contain special justification for inclusion of Arecibo. (Observations with ``ad-hoc'' arrays will also be considered. In this case, proposals should be submitted to Arecibo as specified at http://www.naic.edu/~astro/proposals/proposal.shtml.It is the proposers' responsibility to ensure that telescope time be granted by all observing facilities involved.)

From 2004, Arecibo has used a VLBA4 Data-Acquisition Rack, together with a Mark-5A disk-based VLBI recording system. This allows up to a 1 GBit/s data recording rate. The Mark-5A system also allows Arecibo to participate in real-time e-VLBI with EVN. The addition of an RDBE VLBI digital backend, and Mk5C recorders occurred in 2012. This system permits standard data recording rates of 2-GBit/s.

Robert Minchin 2017-10-30