A progress report on the development and performance of OCTAVE-DAS for VERA, JVN and Japanese e-VLBI(OCTAVE)

The new VLBI observing system (OCTAVE-DAS) have developed based on the VSI-H and VDIF specifications at NAOJ (National Astronomical Observatory of Japan). It consists of 1) a high speed 8-Gsps 3-bit RF direct ADC (OCTAD) enable us to acquire not only wide intermediate frequency but also radio frequency up to 50 GHz and have DBBC functions for VGOS (VLBI Global Observing System), 2) a converter (OCTAVIA and OCTAVIA2) between one 10 GigE port and four 2 Gbps input and output ports conformable to VSI-H, and 3) new recorders (OCTADISK, OCTADISK2 and VSREC) at a rate of 4.5 Gbps and above 8 Gbps and 4) Gbit realtime correlator (OCTACOR) and software correlator system (OCTACOR2) using GICO3 was developed by NICT. These OCTAVE-DAS are connected via 10 GigE network with VDIF and VSI specifications. These components have been used for VERA, JVN (Japanese VLBI network) and KJJVC (Korea-Japan Joint VLBI Correlator). This paper reports a three-year progress since the last General Assembly of the International Union of Radio Science.