The Mark IIIA Correlator System

摘要: The Mark IIIA correlator system, developed at Haystack Observatory, is a second-generation version of the original Mark III correlator which adds significant new capabilities, such as double-speed operation, longer integration periods, and improved internal modelling. One Mark IIIA correlator is currently operational at the U.S. Naval Observatory in Washington, D.C., and another is being readied to replace the Mark III correlator at Haystack.The Mark IIIA correlator can simultaneously process up to 10 baselines of 24-MHz BW data from 5 stations. Experiments including more than 5 stations may be processed with multiple passes through the correlator. The architecture of the correlator allows a future expansion to a maximum of 16 stations. Due to a simple modular design and the low cost of required computer-support equipment, expansion is straightforward and relatively economical.Both astronomy and geodetic data processing are supported by the Mark IIIA system, including spectral line and pulsar gating. In addition, recent work has led to support of space-based VLBI observations; this capability was critical in supporting the first successful space-based VLBI astronomy observations between ground-based antennas and an orbiting satellite in August 1986.