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: adac@jvo.nao.ac.jp

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.