Contribution of the Japanese technology for the International Earth Rotation
Service
Akira Sugiura
Chairman
Committee on Space-Time Measurement Project
Great progress has been made in the science and space geodesy during the past
decade. In these circumstances the International Earth Rotation Service (IERS)
started its activities in precise observations of the Earth rotation. This work
requires a variety of advanced technology, such as Very Long Baseline
Interferometry (VLBI), Satellite Laser Ranging (SLR), Lunar Laser Ranging (LLR)
and Global Positioning System (GPS). These sophisticated observation systems
have greatly changed our views of the nature of Earth so far. For further
extending our scientific knowledge, it is believed essential to develop and
improve the technology of observation systems . Therefore, the IERS designated
our laboratory (CRL) and Haystack Observatory (in USA) as the VLBI Technical
Development Centers (TDC) in October 1990. It is a great pleasure for us to
contribute to the IERS in the technical fields as well as in the experimental
ones. We will make every possible effort to improve the relating technology in
cooperation with other laboratories in Japan.
Establishment of VLBI Technlcal Development Center
Technical Development Center (hereafter TDC) will work
I. to develop new observation technique and new system for more advanced
Earth's rotation observation by VLBI and other space technique,
II. to promote the research of Earth's rotation by supporting the VLBI
technology level,
and
III. to distribute new technology of VLBI.
The TDC not only develop new observation system, but also make efforts to apply
the products to enhance the knowledge of human being through R&D experiments and
exchanging scientists.
Location of the TDC in IERS is shown in Fig.1. In Japan, three Centers are
working for IERS, which are VLBI observation center (NAO), analysis center (NAO)
and TDC. TDC is organized by the Director General of Communications Research
Laboratory. And it is managed under the Space-Time Measurement Project
Committee. The President of the Committee is Director of the Standards and
Measurement Division, who designate the members of the Comittee. Moreover,
Director General requests the special members from the other institutes. The
Committee is to be advised concerning the plan of Technical Development by the
special member.
TDC chooses the development themes for the future IERS activities. And
technical development plan is made in the TDC meeting. Selected theme is
studied both in CRL and at other relating study groups. And technical
information is exchanged with the other TDC (Haystack Obs.) for the
international cooperation.
