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Astronomical Data Analysis Software and Systems VII
ASP Conference Series, Vol. 145, 1998
R. Albrecht, R. N. Hook and H. A. Bushouse, e
Ö Copyright 1998 Astronomical Society of the Pacific. All rights reserved.
ds.
An Archival System for Observational Data Obtained at
the Okayama and Kiso Observatories. III
Eiji Nishihara and Michitoshi Yoshida
Okayama Astrophysical Observatory, National Astronomical
Observatory of Japan, Kamogata, Okayama 719­02, Japan
Shin­ichi Ichikawa, Kentaro Aoki and Masaru Watanabe
Astronomical Data Analysis Center, National Astronomical Observatory
of Japan, Mitaka, Tokyo 181, Japan
Toshihiro Horaguchi
National Science Museum, Shinjuku, Tokyo 169, Japan
Shigeomi Yoshida
Kiso Observatory, University of Tokyo, Mitake, Nagano 397­01, Japan
Masaru Hamabe
Institute of Astronomy, University of Tokyo, Mitaka, Tokyo 181, Japan
Abstract. We present the newly developed version of the Mitaka­
Okayama­Kiso data Archival system (MOKA3). MOKA3 consists of
three parts: 1) a distributed database system which manages the obser­
vational data archive of Okayama and Kiso observatories, 2) a Web­based
data search and request system, and 3) a delivery system for requested
data. The client system of MOKA3 is implemented as a Java Applet
so that many functions, e.g., GUI arrangement, display of preview im­
ages, and conversion of coordinates, can be processed locally on the client
side without accessing the server system. Moreover, environmental data,
such as meteorological data and all­sky images, are also archived in the
database system of MOKA3 in order to increase the utility of its archival
observational data.
1. Introduction
Observational data is one of the most important fundamentals in astronomy,
and so the importance of archiving and reusing observational data is widely
recognized. The original version of MOKA (Mitaka­Okayama­Kiso data Archival
system; Horaguchi et al. 1994; Takata et al. 1995; & Ichikawa et al. 1995) is the
first fully­fledged observational data archival system in Japan. It was developed
for the observational data taken with the Spectro­NebulaGraph (SNG; Kosugi et
425

426 Nishihara et al.
al. 1995) of the 188cm telescope at the Okayama Astrophysical Observatory, and
those taken with the prime focus CCD camera of the 105cm Schmidt telescope
at the Kiso Observatory.
Basically, the original MOKA was not a client­server system. Therefore,
the sites where users can operate MOKA were considerably restricted. In order
to solve this problem, we developed the second version of MOKA (MOKA2 1 ;
Yoshida 1997) which is based on the World Wide Web (WWW). MOKA2 has
been in operation since September 1996. Through the operation of MOKA2,
several points to be improved were clarified. These were with respect to display­
ing preview images, managing database systems, and integrating environmental
data. Then we started to develop the third version of MOKA (MOKA3), which
will be in operation late in 1997. In this paper, we present a technical overview
of MOKA3.
2. System Overview
MOKA3 consists of three parts: 1) a distributed database system which manages
the observational data archive of Okayama and Kiso observatories, 2) a Web­
based data search and request system, and 3) a delivery system of requested
data. The data flow of MOKA3 is shown in Figure 1.
2.1. Distributed Database System
The following three kinds of data files are managed in the MOKA3 distributed
database system. 1) Header information database: Requisite header items are
extracted from header sections of original CCD frames and stored in database
tables. These tables are managed by an ORACLE DBMS (DataBase Manage­
ment System) and used for a search of CCD frames. 2) Header files: In addition
to the header database above mentioned, we stored header files, which are du­
plicate copies of header sections of original CCD frames. These files are plain
text files and used to show detailed information about CCD frames. 3) Pre­
view image files: By binning and resampling, reduced­size preview images are
generated from original CCD frames. They are stored as gzipped FITS files.
These data files are stored in the server machines at Mitaka, Okayama,
and Kiso respectively. Newly produced data from night­by­night observations
are processed into these three kinds of data at their source observatory. These
new processed data are sent to Mitaka, then other observatories copy them
from Mitaka. In MOKA3, this data transfer is achieved by distributed database
mechanism in ORACLE for database files and by ftp­mirroring for header and
preview image files. This mechanism e#ciently copies only new data and keeps
the database at each site consistent.
2.2. Data Search & Request System
The data search and request system of MOKA3 is implemented as a Java ap­
plet. Hence, users can operate MOKA3 with a Java­enabled WWW browser
on any computer connected to the Internet. Searching constraints input in this
1 http://moka.nao.ac.jp/

Archival System for the Okayama and Kiso Observatories. III 427
Figure 1. Data flow of MOKA3.
applet are passed to the DBMS server computer through CGI. SQL statements
corresponding to these constraints are created, and a search is performed by
ORACLE. The results of the search are displayed on the client computer as a
list of frames appropriate to the constraints specified. Users can also display
the detailed header information and/or preview images of selected frames on
the client computer to examine whether these frames are appropriate for their
purpose.
In the above procedure, many functions are processed locally on the client
computer without accessing the server computer. For example, GUI compo­
nents are dynamically switched over in compliance with the user's selection of
searching strategies (e.g., by name or by coordinate). This local processing by
the Java applet reduces load the server computer and the network. Moreover,
as a part of the applet, the viewer of preview FITS images is also implemented
in Java. Therefore, users can flexibly display the preprocessed images with their
favorite display levels, and plot them at any position. In the earlier MOKA2,
such a viewer was prepared as an external viewer of the WWW browser. Hence,
available platforms are restricted. In addition, users must first install the viewer
on their client machine.
The original CCD frames are stored in the observatory where they were
produced. Registered users can utilize these data. MOKA3 has a window to
request for these original data. From this window, the request for selected frames
is automatically generated and sent to the MOKA3 administrator at the source

428 Nishihara et al.
observatory as an e­mail. Registration for MOKA3 data request is also available
from this window.
2.3. Data Delivery System
The administrator who receives the e­mail for a data request checks the propri­
etry period of the data, and sends a distribution tape to the user if no proprietry
problem is found. A mechanism to make a distribution tape corresponding to the
data request e­mail is prepared. This decreases the load on the administrators
at the observatory and makes the distribution of the data quicker.
2.4. Weather Database & Sky Monitor
In addition to the above three main body of MOKA3, access to the weather
database and the all­sky images at Okayama is available from the home page of
MOKA3. They are implemented as independent applets for the present. Because
meteorological conditions severely a#ect the quality of data from ground­based
observations, these environmental data are also archived in the database system
of MOKA3 in order to help users to sift out adequate data from the archive.
Acknowledgments. The study on the data archival system is one of the
projects promoted by the Japan Association for Information Processing in As­
tronomy (JAIPA). This work was supported in part under the Scientific Re­
search fund of Ministry of Education, Science, Sports and Culture (06554001,
07304024 and 08228223), and JAIPA Nishimura foundation. The authors thank
S. Nishimura for his continuous encouragement.
References
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(San Francisco: ASP), 173
Kosugi, G., et al. 1995, PASP, 107, 474
Takata, T., et al. 1995, Publ. Natl. Astron. Obs. Japan, 4, 9
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Software and Systems VI, ed. Gareth Hunt & H. E. Payne (San Francisco:
ASP), 302