Download ppt - JVO

Prototype system of the Japanese Virtual Observatory
Masahiro Tanaka, Yuji Shirasaki, Satoshi Honda, Masatoshi Ohishi, Yoshihiko Mizumoto
(NAOJ), Naoki Yasuda (U. Tokyo), Yoshifumi Masunaga (Ochanomizu U.)
http://jvo.nao.ac.jp/
The Japanese Virtual Observatory (JVO) aims at providing easy access to federated astronomical databases (especially SUBARU, Nobeyama and ALMA) and data analysis environment using the
Grid technology. JVOQL (JVO Query Language) is defined in order to write request conditions for federated databases. The JVO prototype system is developed for the purpose of technical
feasibility study, including functionality of JVOQL, remote operations using Globus toolkit, and automatic search for services. The prototype consists of several components: JVO portal where users
can look up astronomical catalogs and build a query request easily, distributed data servers containing data of Subaru Suprime-Cam and 2MASS, and JVO controller to decompose a request written
in JVOQL into individual queries for data servers. We confirm that this prototype actually works as federated databases and that the Grid service of the Globus toolkit version 3 has adequate
performance for the federation of distributed databases.
Introduction
Increasing amount of
Astronomical Data
Nobeyama
Subaru
ALMA
： ～１TB/yr
： ～20TB/yr
： ～？PB/yr
etc.
Cumbersome task for every instrument:
Data retrieval, transfer, analysis, etc...
JSP
DB Navigator
JSP
•
JVOQL Parser
Scheduler
Executer
Several-hour task in conventional ways.
Five-minute task with JVO !
Astro DB
RFT
Met
aDB
Astro DB
RFT
Scheduler
Remote Execution
with Grid Service
Grid Service
Met
aDB
Grid Service
User DB
Data Analysis
JVO features
１．Grid environment using Globus Toolkit
Globus Toolkit ver.3 is employed for JVO Prototype ver.2. “Grid Service” of
GTK3 is used for remote operation. RFT (Reliable File Transfer) and SFS is
used for file transfer between portal and remote servers.
２．JVOQL (JVO Query Language) for database federation
We defined JVOQL to write search condition to federate distributed database.
JVOQL is based on SQL, widely used as a language for a relational database,
and provides functionalities of cross match and retrieval of image and
spectrum.
User Operation Windows
After authentication, choose
catalogs and specify
retrieval condition using
JVOQL editor.
３．Multi-user and multi-task
JVO includes authentication system. It certifies users, permits access to JVO
system, and manages users’ processes and storage areas.
４．Metadata management
Metadata is information on remote servers, services and observational data.
We defined XML expressions of metadata and stored them into Registry,
which is constructed using XML DB. That enables automated federation of
distributed database and analysis servers, and contents of available
observational data in JVO.
Work flow for
Gravitational lens search
１．Retrieve Subaru catalog data in a
specified region.
↓
２．Calculate brightness
↓
３．Define condition to select quasars.
↓
４．Make a list of pair quasar objects.
↓
５．Retrieve image data of the pair
objects
↓
６．Narrow candidates by analyzing the
image data.
OAI-PMH
Grid Service
Job Status
Executer
Remote Execution
with Grid Service
Grid Service
Status
monotor
OAI-PMH
As an example of research using JVO, here
exhibits a series of processes for searching
gravitational lens object in data obtained
with Subaru telescope.
Server
Info
Registry
(XMLDB)
Server
Info
•
Controller
Grid Service
OAI-PMH
JVO Prototype
Analysis
Command
Simple Analysis
Source Extraction（Sextractor）
• Hyper-Z
• Image Operation
• Photometry
JSP
• Specific Analysis
• Gravitational Lens
• Dust Distribution
• Chemical Evolution
•
VOTable Viewer
• Plotter Image
• Viewer
• Spectrum Viewer
• Multi-catalog Superpose Plot
• Multi-wavelength Image Plot
•
Result (XML)
OAI-PMH
To be used by general education,
amateur astronomers and families
as well as researchers.
Parsed Query
JSP
Data transfer with SFS
JVOQL
Metadata
Query
(XPath)
Status
• Make multi-wavelength research easy
due to unified data manipulation
regardless of observational instruments.
Job
Status
Controller
Job Element
• Internal data analysis reduces data
transfer.
Status
Monitor
OAI-PMH
• Enables observation regardless of time
and place.
JCOQL Editor
•DB Search with Resource finder
•UCD finder
•Name Revolver
•Status Monitor
Servlet
Analysis Interface
Data Display
JSP
•
DB Search with Resource
finder
Met
aDB
Benefit of VO...
Query interface
User Register
• User Authentication
•
Data transfer with SFS
VO is a system to observe “the Universe in
computers”, which is constructed by
employing these information technologies.
User Management
Query Command
(JVOQL)
JVO System
Conventional methods are inadequate.
Information science takes important
roles in Astronomy.
Development
of JVO
User Interface
Combination of Information
technologies and Astronomy
•Web service
•Grid technology
•Data Mining
•Database technology
•Visualization
•etc…
The main purpose of the development of JVO
prototype is to test functionality of employed
technologies. JVO prototype version 2 has
currently been developed.
Retrieval condition is
reflected in JVOQL
Editor.
Result Display Windows
Search result is obtained in the
form of VOTable, which is
international standard to express
table data in the XML form, and
displayed on WWW browser.
Registry is used to find available data
in JVO and to construct work flow of
remote procedure calls.
JVOQL parser decomposes JVOQL,
Scheduler generates work flow, and
Executer performs remote procedure
calls.
It is easy to add new analysis tools
for conducting particular science.
← ↑
Retrieve and display
SXDS data
↑
Retrieve SDSS QSO and
display spectra