IVS 2000 General Meeting Proceedings
[*] [*] [*]


Tsukuba 32-m VLBI Station

Yoshihiro Fukuzaki

Geographical Survey Institute, JAPAN

Abstract:

This report summarizes the activity at the Tsukuba 32-m VLBI station (Fig 1) by the Geographical Survey Institute (GSI) VLBI group. The Tsukuba 32-m VLBI station has participated in several international VLBI sessions. Domestic experiments (JADE sessions) are carried out periodically using GSI's domestic network, which includes the Tsukuba 32-m VLBI station. We have a plan to increase the JADE sessions and perform collocation surveys at the Tsukuba and Aira stations.

1. Activities

Tsukuba 32-m VLBI station has participated in several international VLBI experiments that are listed in Table 1.

GSI has five permanent stations in Japan. Distributions of these stations are shown in Fig 2. The network is named GARNET (GSI Advanced Radiotelescope Network). In 1999 and 2000, domestic experiment using GARNET was carried out four times a year. This session is named JADE (Japanese Dynamic Earth observation by VLBI). From JADE-0003 Gifu station with 3m antenna owned by Gifu University has participated in JADE session. The network has now six stations and ten baselines. The result of the JADE sessions is available on the GSI VLBI Web page (http://vldb.gsi.go.jp/sokuchi/vlbi/english).

A tie experiment among the stations that have a large antenna, Kashima 26-m, Kashima 34-m and Tsukuba 32-m, was carried out in 2000. This session is named JPNTI. The purpose of JPNTI sessions is to transfer the coordinates of Kashima 26-m and Kashima 34-m established by a long period of observation to Tsukuba 32-m VLBI station. Four KSP stations also participate in this session.

The data for CORE-OHIG6,7,9,12 sessions in Syowa station, Antarctica were dubbed from K4 into MarkIIIa at Tsukuba 32-m VLBI station. These data were correlated at Bonn Correlator and analyzed at GSFC.

  
Figure 1: Tsukuba 32-m VLBI antenna.
\begin{figure}% figure environement\begin{center}% center environment\parb... ...lose the paragraph box\end{center} % end of center environment\end{figure}


 
 
Table 1: International experiments at Tsukuba 32-m VLBI station after Nov. 1999
Experiment Code
CORE-A CA075,76,77,79,80,81,82,83
CORE-1 C1001,02,03,04,05,06,07
CORE-B CB701,702
VLBA RDV19,20,21,22,23,24
JPNTI JPNTI2,3,4,5,6
Other NEOS-A351, SURVEY001, CRF09, APSG07

  
Figure 2: GSI domestic VLBI network and Gifu station.
\begin{figure}% figure environement\begin{center}% center environment\parb... ...lose the paragraph box\end{center} % end of center environment\end{figure}

2. Changes

The staff of VLBI group at GSI has changed. Table 2 lists the present staff.

Six months after installing Tsukuba 32-m antenna, the Azimuth rail, which was 73 kg per meter and 10 cm width, was cracked because the stress from the wheel was larger than the value designed by the antenna manufacturer. In April 1999, the rail was replaced with a larger one (Fig 3). So far, no significant problems with the rail have occurred. By this replacement of Azimuth rail, the height of the reference point of Tsukuba 32-m antenna has changed +43.7mm.

GSI's internet domain name has been changed from gsi-mc.go.jp to gsi.go.jp since January 2001.


 
 
Table 2: Staff working at GSI VLBI group
Name Position Jobs
Shigeru MATSUZAKA IVS Networks Representative  
Yoshihiro FUKUZAKI Leader of VLBI group  
Tadayuki AKIYAMA Collocation chief Collocation, Operation
Kousei SHIBA Operation chief
Experiments Coordination,
Operation
Kazuhiro TAKASHIMA Visiting scientist at GSFC
Improvement of software
for VLBI analysis
Masaru YAZAWA Analysis chief Baseline Analysis, Operation
Shinobu KURIHARA Operator Baseline Analysis, Operation
Michiko ONOGAKI Operator
Antenna and H-maser maint.,
Operation
Kohei MIYAGAWA Correlation chief Correlation, Operation
Kyoko KOBAYASHI Assistant Correlation, Operation

  
Figure 3: Azimuth rail replacement (Left: before Right: current).
\begin{figure}% figure environement\begin{center}% center environment\parb... ...lose the paragraph box\end{center} % end of center environment\end{figure}

3. Prospect

It is planned to increase JADE sessions from four times a year to eight.

IGS station (TSKB) is close by the 32m VLBI antenna (300m) at Tsukuba station, and a GPS station of GSI Earth Observation Network is close by the VLBI antenna at Aira station. Collocation survey at Tsukuba and Aira station will be performed in 2001.

Bibliography

1
Ishihara, M., K. Nemoto, M. Iwata, K. Shiba, K. Takashima, and S. Matsuzaka: Tsukuba 32-m VLBI station, IVS 1999 Annual Report, pp.115-118, August 1999

2
Ishihara, M., K. Nemoto, M. Iwata, K. Shiba, K. Takashima, and S. Matsuzaka: Tsukuba VLBI Center, IVS 1999 Annual Report, pp.160-163, August 1999

3
Takashima, K., S. Kurihara, M. Ishihara, K. Nemoto, M. Iwata, K. Shiba, M. Onogaki, and K. Kobayashi: Status and Results of GSI Domestic VLBI Networks, Bull. Geograph. Surv. Inst., Vol. 46, pp.1-9, March 2000
[*] [*] [*]
IVS 2000 General Meeting Proceedings