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Construction of the Japanese Virtual Observatory (JVO)
Abstract : The National Astronomical Observatory of Japan (NAOJ) has been operating several large astronomical facilities, such as the SUBARU telescop, the 45 m radio telescope and the Nobeyama Millimeter Array, and plans to construct the ALMA under close collaborations with the US and the EU. Since January 2002, the NAOJ has been connected to the SuperSINET with 10 Gbps, and it has become possible to provide huge amount of observed multi-color data and analyses facilities to other astronomical institutions. Thus we have started the Japanese Virtual Observatory (JVO) project since April 2002. JVO utilizes the Grid technology to combine several remote computational facilities. We have completed to define the query language for the JVO, and have been designing on the deployment of JVO components. We plan to construct a JVO-prototype by the end of 2002. More information is provided at:
Yoshihiko MIZUMOTO, Masatoshi OHISHI, Naoki YASUDA, Yuji SHIRASAKI, Masahiro TANAKA (NAOJ), Yoshifumi MASUNAGA (Ochanomizu Univ. and NAOJ), Ken MIURA, Hirokuni MONZEN, Kenji KAWARAI, Yasuhide ISHIHARA, Yasushi YAMAGUCHI and Hiroshi YANAKA (Fujitsu Ltd.)Contact Address: [email protected]
User’s ownservice
User’s ownservice
Security mngmt Security mngmt Resource mngmt Resource mngmt
MVC
MVC
MVC
JVOPortalJVO
Portal
Astronomical CatalogQuery Service
Astronomical CatalogQuery Service
Globus Toolkit
Catalog DB
ServiceRegistryServiceRegistry
Researcher
Browser for JVOBrowser for JVO
Viewerfor JVOViewerfor JVO Data Archive
ServiceData Archive
Service
Data manage DB
DataVirtual Observationexecution service
Virtual Observationexecution service
Data Analysisservice
Data Analysisservice
ServiceRegistryServiceRegistry
Other VO servicesOther VO services
Other Catalogservices
Other Catalogservices
Globus Toolkit
JVO GRID EnvironmentOther GRID Environment
UDDI server (FreeSoft)
WebBrowser
WebブラウザCommands callable
from GT2
GlobusToolkit V2
Data managementData management
skycat
Security mngmt Security mngmt Resource mngmt Resource mngmt Data managementData management
Super SINET is an ultrahigh-speed network intended to develop and promote Japanese academic researches by strengthening collaboration among leading academic research institutes. The National Institute of Informatics has been operating the network since January 4, 2002. The Internet backbone connects research institutes at 10 Gbps and the leading research facilities in the research institutes are directly connected at 1 Gbps.
Ultrahigh-speed network and JVO
JVO@NAO
ALMA @ Chile
Radio Telescope @ Nobeyama
Subaru Telescope @ Hawaii
JVO @ NAOJ
Subaru 0.3m~20m ~20TB/yr
Nobeyama 10GHz~230GHz ~1TB/yr
ALMA (plan) 30GHz~950GHz ~PB/yr
Properties of the astronomical data base utilized by JVO
Registry
=
Inter-national
VO
Schematic diagram of JVO system
Distributed computing system
Distributed data base system Users
10Gbps Super SINET, linked with GRID technology
GRID
JVO @ NAOJ
- JVO consists of a distributed computing system (DCS) which is deployed over the GRID technology and a registry which provides information required for DCS to query the distributed DB system.- All the computers of the DCS have an equivalent function and any of them can takes place of another machine, which is important for robustness of JVO system.- Selection of a machine for servicing the JVO users is automatically performed by GRID system based on the system load average.- JVO has inter-operability with the other VOs.
The JVO Query Language
JVOQL has an ability to query image data without referring to catalogs. This ability is useful for multi-color or multi-epoch analyses. The above JVOQL example shows how to obtain R-band
select s.a, t.a, ...from SUBARU.R s, 2MASS.K t, ...where (s.AREA() OVERLAP t.AREA()) as a
• Federate with more data Data of SUBARU open use/Nobeyama Radio Observatory• Interoperability with other VOs
Toward International VO• CPU intensive image analysis tools
Deconvolution, image subtraction, ...Run on PC cluster via GRID
• Data mining / visualization toolsManage huge amount of data
Future Plan
First of all, researchers provide the JVO with simple instructions how they plan to use their own ''Virtual Observation''. The JVO portal interprets them and generates a work flow through consulting the UDDI servers, where available JVO services are registered. Based on the work flow, built-in or user-defined services are called. The GRID framework is used for dynamical assignment of distributed resources according to their availabilities. Execution results of the work flow are transferred through GridFTP and presented to the researchers with the skycat, etc.
Three-Tiered Design of the JVO Prototype
The JVO prototype is now under development. The design of the JVO prototype is shown as a schematic diagram. We adopted to use the Globus Toolkit V2 for our prototype. However we also take into account the Web service concept which will be included in the Globus Toolkit V3.
The JVO, the distributed data base systems of Subaru and Nobeyama observatories, and astronomers in the research institutes are linked over
create view myEROtable asselect s.Bmag, s.Rmag, t.Hmag, t.Kmag, ..., sr.BOX(POINT(s.ra,s.dec),w,h) as Rimage, tk.BOX(POINT(s.ra,s.dec),w,h) as Kimage, ...from SUBARU s, 2MASS t, ..., SUBARU.R sr, 2MASS.K tk, ...where XMATCH(s,b,...) < 3 arcsec and (s.Rmag-t.Kmag) > 6 mag and BOX(POINT(ra0,dec0), w0, h0) and ...
Specify search area with the same syntax as cutout image specification.
Create view with the user specified name in JVO system.
Select attributes from each catalog server. Column names can be expressed in UCD.
Select the catalog server.
Select the image data server.
Cross-match distributed catalogs.
Query condition based on distributed catalog.
Select cutout images from each image data server.Image area can be specified by BOX or CIRCLE operand.
The JVO Query Language (JVOQL) is used in JVO as a language to specify a variety of user queries. The JVOQL has been designed to keep upward-compatibility with the standard relational database language, Structured Query Language (SQL), to enable in handling image data and cross-matching among distributed databases. The interpreter of JVOQL communicates with the registry of available databases and issues query sequences to distributed databases.
SUBARU.R s 2MASS.K t
s.AREA() t.AREA()
AREA table
cutout request
OVERLAP
s ta1a2a3
Par
titio
n to
smal
l seg
men
t
http://jvo.nao.ac.jphttp://jvo.nao.ac.jp
the GRID technology through the 10Gbps Super SINET (http://www.sinet.ad.jp/english/).
images taken by SUBARU and K-band images by 2MASS in an area where both SUBARU and 2MASS observed. The operand “OVERLAP” returns overlapped area of the two data. Similarly the operand “X.AREA()” returns the observed area of server X.