<title>Very long baseline connected interferometry via the ATM network</title>

Abstract

The Communications Research Laboratory (CRL), the National Astronomical Observatory (NAO), the Institute of Space and Astronautical Science (ISAS), and the Telecommunication Network Laboratory Group of Nippon Telegraph and Telephone Corporation have developed a real-time VLBI array, maximum baseline-length was 208 km. The very long baseline interferometry (VLBI) observed data is transmitted through a high-speed asynchronous transfer mode (ATM) network (2,488- Gbps [STM-16/OC-48] ATM network) instead of being recorded onto magnetic tapes. The system was composed of two real-time VLSI networks: the Keystone Project network of CRL (which is used for measuring crustal deformation in the Tokyo metropolitan area), and the OLIVE (optically linked VLBI experiment) network of NAO and ISAS which is used for astronomy (space-VLBI). The acquired VLBI data were corrected via the ATM network and the cross-correlation processing were done simultaneously. A radio flares on the weak radio source (HR1099) and weak radio sources were detected.