HR: 0800h
AN: G41C-0377    [Abstracts]
TI: Development of a New VLBI Sampler Unit Dedicated to e-VLBI for Near Real-Time Monitoring of Earth Rotation
AU: * Kondo, T
EM: kondo@nict.go.jp
AF: Kashima Space Research Center/NICT, 893-1 Hirai, Kashima, Ibaraki, 314-0012 Japan
AU: Koyama, Y
EM: koyama@nict.go.jp
AF: Kashima Space Research Center/NICT, 893-1 Hirai, Kashima, Ibaraki, 314-0012 Japan
AU: Takeuchi, H
EM: ht@nict.go.jp
AF: Kashima Space Research Center/NICT, 893-1 Hirai, Kashima, Ibaraki, 314-0012 Japan
AU: Kimura, M
EM: mkimura@nict.go.jp
AF: Kashima Space Research Center/NICT, 893-1 Hirai, Kashima, Ibaraki, 314-0012 Japan
AB: National Institute of Information and Communications Technology (NICT) has developed three models of VLBI samplers, ADS1000, ADS2000 and K5/VSSP, dedicated to near real-time VLBI observation (e-VLBI) through a high-speed network connection for monitoring earth orientation parameters. Among these three models, the K5/VSSP, which is designed to be a PCI bus board mountable on a general purpose PC, has broadened the base for VLBI users, i.e., any PC equipped with the K5/VSSP PCI-bus board can be a VLBI recorder, and the data transfer through the Internet is easily realized. With the advent of K5/VSSP the development of software correlator also greatly progressed. Recently we have developed a new VLBI sampler named K5/VSSP32 as a successor to the K5/VSSP. Maximum sampling frequency is increased up to 32MHz. When the number of quantization bit is limited to one, the sampling frequency of 64MHz is possible. Moreover USB 2.0 (Universal Serial Bus specification revision 2.0) is adopted as an interface to connect the sampler with a host PC. It is hence possible to use note book PCs for VLBI observations if it is desired. Specifications are summarized in Table 1. We will report the results of some test observations using K5/VSSP32 at the meeting. Table1. Specifications of VLBI samplers \begin{tabular}{ccccc} \hline model & ADS1000 & ADS2000 & K5/VSSP & K5/VSSP32
\hline # of CH & 1 & 16 & 4 & 4
per unit & & & &
Max & & & &
sampling & 1024MHz & 64MHz & 16MHz & 32MHz
frequency & & & &
# of & 1,2 & 2 & 1,2,4,8 & 1,2,4,8
AD bits & & & &
Max data rate & 2048Mbps & 2048Mbps & 64Mbps & 256Mbps
per unit & & & &
Output & VSI-H & VSI-H & PCI-bus & USB 2.0
\hline \end{tabular}
DE: 1239 Earth rotation variations
DE: 1243 Space geodetic surveys
DE: 1294 Instruments and techniques
SC: Geodesy [G]
MN: Fall Meeting 2005