Very Long Baseline Connected Interferometry via the STM-16 ATM Network
نویسندگان
چکیده
Manuscript received May 28, 1999. † The authors are with Communications Research Laboratory, Koganei-shi, 184-8795 Japan. †† The authors are with NTT Multimedia Networks Laboratories, Musashino-shi, 180-8585 Japan. ††† The author is with NTT Advanced Technology Corporation, Yokohama-shi, 244-0801 Japan. †††† The authors are with National Astronomical Observatory, Mitaka-shi, 181-8588 Japan. ‡‡† The author is with Institute of Space and Astronoutical Science, Sagamihara-shi, 229-8510 Japan. ‡‡‡ The authors are with Kashima Space Research Center, Communications Research Laboratory, Ibaraki-ken, 314-0012 Japan. SUMMARY The Communications Research Laboratory (CRL), the National Astronomical Observatory (NAO), the Institute of Space and Astronoutical Science (ISAS), and the Telecommunication Network Laboratory Group of Nippon Telegraph and Telephone Corporation (NTT) have developed a very-long-baseline-connected-interferometry array, maximum baseline-length was 208 km, using a highspeed asynchronous transfer mode (ATM) network with an AAL1 that corresponds to the constant bit-rate protocol. The very long baseline interferometry (VLBI) observed data is transmitted through a 2.488Gbps [STM-16/OC-48] ATM network instead of being recorded onto magnetic tape. By combining antennas via a high-speed ATM network, a highly-sensitive virtual (radio) telescope system was realized. The system was composed of two real-time VLBI networks: the Key-StoneProject (KSP) 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). These networks operated in cooperation with NTT. In order to realize a virtual telescope, the acquired VLBI data were corrected via the ATM networks and were synthesized using the VLBI technique. The cross-correlation processing and data observation were done simultaneously in this system and radio flares on the weak radio source (HR1099) were detected. key words: very long baseline interferometry, STM-16/OC-48, data synchronization, virtual telescope
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