4. Technical Reports
4.1 Key Stone Project
Automatic Observation System (Takahiro Iwata)
VLBI is one of the most accurate technique for geodetic measurements.
However, it is not suitable for daily observations because much
man-power is necessary for both observations and data processing.
The purpose of the Keystone project promoted by CRL is to detect regional
crustal deformations, considered as precursors of large earthquakes, therefore
continuous daily observations are strongly desirable. Especially
high reliability is required for the system to perform the
continuous observations not disturbed by instrument malfunctions.
Fully automatic operation is also required. We have designed
the KSP system so as to meet both these requirement.
Stations
Each station is equipped with two kinds of computers.
One is a controlling computer which controls the observation instruments, such
as an antenna and a recorder according to schedule prepared in advance.
The other is a monitoring computer which gathers basic
data, such as meteorological data, sytem noise temperature, and status
of each instrument.
Central station
Koganei and Kashima function as a central station and a sub-central station.
Both stations are equipped with concentrated controlling computers which
control and monitor systems at each station via a computer network.
An operator at the central or sub-central station can therefore know
the status of each station.
Computer network
A WAN (Wide Area Network), which is a dedicated digital communication
link, connects Kashima, Koganei, Miura and Tateyama.
Furthermore we plan to have a backup digital link between Kashima and Tateyama.
Each station is also equipped with a telecommunication line for data
transfer. Remote operation through this line is planned to
recover the computer system as a backup.
Data recording
The data recording is performed by the K4 data recorder built in the DMS-24
automatic tape changer. The DMS-24 enables operatorless observations
for 24 hours. We aim to do real-time data transfer to the correlator
at the central station in the future.
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