Haystack instrumentation

At the Westford antenna site, which serves as both an operational VGOS telescope and a NASA VGOS network research and development site, the entire back end of the signal chain is VGOS-compliant. A team is upgrading the backend signal chain hardware for all control room components, including the radio frequency distributor, up-down converter, ROACH2 digital backend (R2DBE), and Mark 6 recorders. The improvements bring Westford’s backend up to the VGOS requirements by upgrading from four 512 MHz frequency bands to four 1 GHz bands, with data sampling rates of 2 giga-samples per second, with 4 giga-samples per band supported.At the Westford antenna site, which serves as both an operational VGOS telescope and a NASA VGOS network research and development site, the entire backend of the signal chain is VGOS-compliant. A team is upgrading the backend signal-chain hardware for all control room components, including the radio frequency distributor, up-down converter, ROACH2 digital backend (R2DBE), and Mark 6 recorders. The improvements bring Westford’s backend up to the VGOS requirements by upgrading from four 512-MHz frequency bands to four 1-GHz bands, with data sampling rates of 2 giga-samples per second (Gsps), and 4 Gbps per band supported.

Simultaneously, a software and engineering development team is streamlining and automating the correlation and post-processing of VGOS session data, which requires several additional steps compared to legacy geodetic VLBI systems in order to reduce both statistical and systematic errors. These occur at various stages: prior to correlation (clock model and sampler delay adjustment), fringe-fitting (phase and delay corrections), and geodetic analysis (cable delay corrections). These procedures are in preparation for broad distribution at correlators worldwide, and upcoming meetings.At the Westford antenna site, which serves as both an operational VGOS telescope and a NASA VGOS network research and development site, the entire back end of the signal chain is VGOS-compliant. A team is upgrading the backend signal chain hardware for all control room components, including the radio frequency distributor, up-down converter, ROACH2 digital backend (R2DBE), and Mark 6 recorders. The improvements bring Westford’s backend up to the VGOS requirements by upgrading from four 512 MHz frequency bands to four 1 GHz bands, with data sampling rates of 2 giga-samples per second, with 4 giga-samples per band supported.