Transmission of data directly from the stations to the correlator provides potentially much faster turn-arounds, as days-worth of shipping delay can be avoided. This can open the way for target-of-opportunity observations of transient phenomena, without concern for having a pre-deployed supply of recording media in place at all stations outside network sessions. Further, considerably faster feedback can be provided to stations, potentially avoiding problems that may otherwise have remained undetected for some time. During fringe-test observations at the beginning of network sessions, some stations already ftp a small amount of data to JIVE, and indeed some problems have been detected in time to repair prior to the session. For future correlators, e-VLBI also provides the opportunity for bandwidths exceeding our current 1Gb/s limit.
JIVE participated in iGrid2002, an international grid application test-bed event held in Amsterdam in September 2002. Our project demonstrated data rates over existing research networks. Data recorded onto disk at Jodrell Bank were transmitted to Amsterdam, where packet tracing and transit times were checked, and then forwarded up to Dwingeloo. After buffering onto disk, they were correlated against a tape from Wb, and a direct connection back to iGrid2002 allowed simultaneous display of the resulting fringes.
A more ambitious test will be the ``EVN-NREN Proof of Concept" project, which aims to provide a real-time connection for five EVN telescopes (outside the Netherlands) to JIVE. These connections will be via individual national research & education networks (NRENs) and GÉANT, a pan-European research network. The status of the ``last-mile" problem -- connecting the telescopes themselves to the closest NREN node -- differs from station to station. An EVN goal for this project would be same-day imaging of sustained 1Gb/s observations. Considerably more information about the iGrid2002 demonstration and the EVN-NREN PoC can be found on EVN web-page under the ``e-VLBI" menu item.
To help process small amounts of fringe-test observations that have been ftp'ed into JIVE, we have entered negotiations with CRL in Kashima to obtain a version of their KSRC/CRL VLBI software correlator. They have already found Wb-Ks fringes using Wb data ftp'ed to Kashima and transformed from Mk5 to K5 format (also discussed under the ``EVN TOG" web page, as above in §4.1). Use of such a software correlator would permit rapid investigation of smaller amounts of data without impacting the operations of the main correlator.
The week after the Leipzig meeting, JIVE hosted the e-VLBI Workshop. Abstracts and most presentations can be downloaded from the workshop web-page, which is linked from the main JIVE web-page.