Network Determination and Timeliness of the Rapid Sessions

The latency table shows that 77.3% of the IVS-R1 sessions were processed within 15 days. Most of the sessions were processed within 13 to 14 days. In 2002, there were some start-up problems and 20 sessions (40.8%) were delayed. The latency improved for the next few years until 2007, when 22 sessions (42.3%) were delayed because the Tsukuba data had to be e-transferred to Haystack and shipped to Bonn. The latency improved in July 2007 when Bonn and Tsukuba had a direct connection. The latency increased again in 2011 when 18 sessions (36%) were delayed. The 36% is attributed mostly to problems with the DiFX Software Correlator. The IVS-R1s were processed by Bonn, Haystack, and the Washington Correlator from 2002 through 2006. Starting in 2007 the IVS-R1s were mainly processed by the Bonn Correaltor.