Hello!

Ajit KembhaviIUCAAPune, IndiaVirtual Observatories

The Astronomer Vermeer 1632-1675Data Storage and RetrievalThe Library of Alexandria 3rd Century BC

The Data AvalancheImmense amounts of data are being produced by large telescopes using large area detectors.Terabytes of data are now available, and Petabytes will soon be available from frequent all sky imaging.

Vast databases are also being produced through simulations.

Wavelength CoverageThe data spans the electromagnetic spectrum from the radio to the gamma-ray region.Obtaining, analysing and interpreting the data in different wavebands involves highly specialised instruments and techniques.The astronomer needs new tools for using this wealth of data in multiwavelength studies.

Stars in the Milky Way

The Hertzsprung-Russell Diagram

The AllianceMembers of the IVOA

Interactions

Virtual Observatories

Provide tools for data analysis, visualization and mining.Develop interoperability concepts to make different databases seamless.Manage vast data resources and provide these on-line to astronomers and other users.

Empower astronomers by providing sophisticated query and computational tools, and computing grids for producing new science.

VO Schema

IVOA Technology Initiatives The IVOA has identified six major technical initiatives to fulfill the scientific goal of the VO concept.IVOA-LISTS

REGISTRIES: These collect metadata about data resources and information services into a queryable database. The registry is distributed. A variety of industry standards are being investigated.

DATA MODELS: This initiative aims to define the common elements of astronomical data structures and to provide a framework to describe their relationships.

UNIFORM CONTENT DESCRIPTORS: These will provide the common language for for metadata definitions for the VO.

DATA ACCESS LAYER: This provides a standardized access mechanisms to distributed data objects. Initial prototypes are a Cone Search Protocol and a simple Image Access Protocol.

VO QUERY LANGUAGE: This will provide a standard query language which will go beyond the limitations of SQL.

VOTable: This is an XML mark-up standard for astronomical tables.

Science InitiativesMany IVOA projects have active Science Working Groups consisting of astronomers from a broad cross-section of the community representing all wavelengths.The focus here is to develop a clear perception of the scientific requirements of a VO.Projects within the working groups will develop new capabilities for VO based analysis.This will enable the community to create new research programs and to publish their data and research in a more pervasive and scientifically useful manner.

A collaboration between IUCAA and PSPL, with a grant from the Ministry of Communications and Information TechnologyVirtual Observatory -India

IUCAA

Persistent Systems Pvt. Ltd., Pune

Virtual Observatory - India

Data Archives and Mirrors at VO-I SDSS 2Mass 2DFGRS 2QZ FIRST NVSS Vizier, Aladin, ADSChandra

Data Catalogs & Web services at IUCAA

Catalogs

Catalog

Description

2dfQSO

Size : 4 MB

2dfGRS

Size : 4 GB

Organized as mSQL

2MASS

Size : 42 GB

Sky Survey

Size : 13 GB

FIRST

Size : 192 GB

Web Services

1) VizieR Services

The most complete library of astronomical catalogues (e.g. Guide Star catalogues, USNO-B1)

Tools to select, extract, format records matching certain criteria.

2) Anglo-Australian 2DF System

Query Tool to select records from the 2DF catalogue.

Display Skymap & Spectrum (FITS) of objects in 2DF catalogue.

SDSS Data Features

Size

:900 GB

DBMS

:Microsoft SQL (MS-SQL)

Contains: Spectroscopic data

Tiling data

User

Interface

Client

Submit Query/Request

User

Search MS-SQL Database

MS-SQL

Server

Output

Process Query

Output : 1) HTML

2) XML

3) CSV

SDSS Query Architecture

Fast Computing Four Alpha Server ES-45 machines

Each with 4 processors Alpha 21264C RAM 3 x 8 GB + 12 GB

Fast, Low latency interconnect Memory channel Architecture (MCA)

1 TB SCSCI storage

Trucluster clustering environment (Tru64 Unix, DecMPI, openMP)

VO-India Software ProjectsVOPlot Visualizer for catalogue data VOTable C++ Parser VOTable Streaming writer Data Converters Fits Browser User interfaces and query tools Applications beyond astronomy

All tools have web-based and stand alone versions

The VOPLOT CollaborationVisualization and simple statistics of catalogue data. Integration with sky atlases.

The VOPlot CollaborationA VO-I + CDS collaboration First conceived as a web-based tool for Vizier Then integrated with Aladin VOPlot is now also a stand alone system It has been integrated with many data bases

VOPlot Sonali Kale, K.D. Balaji et. Al.

SDSS J125637-022452High proper motion L-subdwarfOptical spectra of mixed late M and mid L typeOnly the third L subdwarf known

Positions 1986-2000Proper motion 0.617 arcsec / yr

AVO Prototype DemoAstrogrid:Astronomy Catalogue ExtractorAVO: Aladin+SEDVO-India:VOPlot

FITS ManagerView, create and add to FITS filesConvert to other formats

Pallavi KulkarniFits-manager

VOTable Java Streaming WriterActs on a data array in memoryto convert it to the VOTable form, which is streamed row by rowto an output file. Very large VOTables can be written without excessive memory.

Pallavi KulkarniVOTable-Java

Thank You

VOTableThis is a new data exchange standard produced through efforts led by Francois Ochsenbien of CDS, Strasbourg and Roy Williams of Caltech.VOTable is in XML format. Physical quantities come with sophisticated semantic information.

VOTableThe format enables computers to easily parse the information and communicate it to other computers.

Federation and joining of information become possible and Grid computing is easier.

VOTable parsers have been developed in Perl, Java and C++.

Enhancements and extensions are being considered.Streaming ParserNon-streaming Parser

VOTable Data The data part in a VOTable may be represented using one of three different formats:

FITS : VOTable can be used either to encapsulate FITS files, or to re-encode the metadata. BINARY : Supported for efficiency and ease of programming, no FITS library is required, and the streaming paradigm is supported. TABLEDATA : Pure XML format for small tables.

C++ VOTable Parser Motivation:

Provide a library for API based access to VOTable files.APIs can be directly used to develop VOTable applications without having to do raw VOTable processing.Streaming and Non-streaming versions are available.

Sonali Kale, Sudip Khanna

C++ VOTable Parser Salient Features:Implemented as a wrapper over XALAN-C++.XALAN-C++ is a robust implementation of the W3C recommendations for XSL Transformations (XSLT) and the XML Path language (XPath).XPath queries can be used to access the VOTable data.

Project DesignVTableMetadataFieldLink CollectionField CollectionLinkValuesLinkLink CollectionOption CollectionmaximumminimumRowRow CollectionTable DataColumn CollectionOptions

IUCAA HPC Facility Hercules Four Alpha Server ES-45 machines Each with 4 processors Alpha (21264C)1.25 GHz clock speed Cache on chip: 64 Kb I, 64 Kb-D Cache : 16 Mb ECC DDR RAM 3 x 8 Gb + 12 Gb Fast, Low latency interconnect Memory channel Architecture (MCA) High volume Storage 1 Tera-byte SCSCI Trucluster clustering environment (Tru64 Unix, DecMPI, openMP)ES-45Specfp2000: 1327Linpack 1000x1000: 6847Co-proposed by : Ajit KembhaviT. PadmnabhanTarun Souradeep

HPC Team : Sarah PonthratnamSunu EngineerRajesh NayakAnand Sengupta

> 30 G flopsPreliminary HPL benchmark

Virtual Observatory - IndiaIUCAAPersistent Systems

NVO-PeopleCaltech, Fermilab, JHU, NASA/HEARC, Microsoft, NCSA/UIUC, NOAO, NRAO, Raytheon ITS, SDSC/UCSD, SAO/CXC, STScI, UPenn, UPitts/CMU, UWis, USC, USNO, USRA, CVO

Virtual Observatory - India Ajit KembhaviInter-University Centre for Astronomy and Astrophysics Pune, India

Virtual ObservatoriesProvide tools for data analysis, visualization and mining.Develop interoperability concepts to make different databases seamless.Manage vast data resources and provide these on-line to astronomers and other users.Empower astronomers by providing sophisticated query and computational tools, and computing grids for producing new science.

TerapixJodrell Bank

Registry and DIS

High Volume StorageRaid 5, 4 Terabyte

CVO CollaborationsThere are three major projects at the CVO involving collaborations with other VO.CVO is collaborating with the German Astrophysical VO to incorporate ROSAT X-ray data and catalogues into the CVO system.CVO is collaborating with the Australian VO.to incorporate 2Qz and 2DF galaxy spectra into the CVO database.CVO is an associate member of NVO and is have put in place some components of the NVO galaxy morphology demo.

Science InitiativesMany IVOA projects have active Science Working Groups consisting of astronomers from a broad cross-section of the community representing all wavelengths.The focus here is to develop a clear perception of the scientific requirements of a VO.Projects within the working groups will develop new capabilities for VO based analysis.This will enable the community to create new research programs and to publish their data and research in a more pervasive and scientifically useful manner.

Australian VO CollaborationsThe distributed volume renderer (dvr) software, is a tool for rendering large volumetric data sets using the combined memory and processing resources of Beowulf like clusters.A collaboration between the Melbourne site of Aus-VO and AstroGrid aims to develop the existing dvr software into a grid-based volume rendering service. Users will be able to select FITS-format cubes from a number of "Data Centres",have the data transferred to a chosen rendering cluster, and then proceed to visualise the volume of data remotely (See Demo).

C++ VOTable ParserInitial version - Released on May 31st , 2002. - Support only for reading of tables. - Support only for pure-XML TABLEDATA and not for BINARY or FITS data streams. - Runs on Windows NT 4.0, Windows 2000 and RedHat Linux 7.1.

Future enhancements - Can be incorporated quickly and efficiently.

Parser Design Class Details VTable: In memory representation of a single from the element in VOTableTableMetaData: Contains MetaData (Fields, Links and Description)Resource: Represents the element in the VOTable. TableData: Contains Rows Field: Representation of from VOTable Row: Representation of from VOTable Column: Representation of from VOTable

Parser Design API Typical Operations File Level I/O RoutinesOpen VOTable file Close VOTable file

Table I/O Operations Get number of rows Get number of columns Get column(field) information (column name, column number, etc.)Accessing table data

Parser ImplementationDevelopment on Windows NT 4.0 platform using VC++. Ported to RedHat Linux 7.1/gcc-2.96 with zero effort.18 C++ classes representing various elements of the VOTable format.8500 lines of C++ code written for V1.1 releaseProject start date: April 7th 2002V1.1 Release: May 31st 2002Current status: V1.2 design in progress

What is in Release V1.1Parser to serve as a building block for developing VOTable based applications.Can be easily used by users of CFITSIO library.Supports powerful XPath queries against VOTable files.The first version of the VO Table parser can now be downloaded:

http://vo.iucaa.ernet.in/~voi/html/infopage.html

VOTable Parser Demo

Serves as a tutorial to help understand the basic APIs provided by the VOTable parser.

Demonstrates how to access the data and metadata elements of a VOTable file.

Future WorkDevelop APIs for writing data in VOTable format.Develop APIs for supporting IMAGE data and FITS files in VOTable.Enhance existing API set to allow more elaborate and flexible operations on VOTable files.Support future VOTable versions.Develop applications for conversion between FITS and VOTable formats.

ReferencesThe first version of the C++ parser can now be downloaded from the VO-India websitehttp://vo.iucaa.ernet.in/~voiVOTable Details: http://vizier.u-strasbg.fr/doc/VOTable/XALAN http://xml.apache.org/xalan-c/index.htmlXPATH http://www.w3.org/TR/xpath

Virtual Observatory - India

SDSS Data Features

Size

:900 Gb

DBMS

:Microsoft SQL (MS-SQL)

Data Contains:1) Spectroscopic data

2) Tilling data

User

Interface

Client

Submit Query/Request

User

Search MS-SQL Database

MS-SQL

Server

Output

Process Query

Output : 1) HTML

2) XML

3) CSV

SDSS Query Architecture

Data Catalogs & Web services at IUCAA

Catalogs

Catalog

Description

2dfQSO

Size : 4 MB

2dfGRS

Size : 4 GB

Organized as mSQL

2MASS

Size : 42 GB

Sky Survey

Size : 13 GB

FIRST

Size : 192 GB

Web Services

1) VizieR Services

The most complete library of astronomical catalogues (e.g. Guide Star catalogues, USNO-BI.

Tools to select, extract, format records matching a certain criteria.

2) Anglo-Australian 2DF System

Query Tool to select records from the 2DF catalogue.

Display Skymap & Spectrum (FITS) of objects in 2DF catalogue.

Star Positions

REGISTRIES: These collect metadata about data resources and information services into a queryable database. The registry is distributed. A variety of industry standards are being investigated.DATA MODELS: This initiative aims to define the common elements of astronomical data structures and to provide a framework to describe their relationships. UNIFORM CONTENT DESCRIPTORS: These will provide the common language for for metadata definitions for the VO.

What we are doing and why we are doing it.Contains brief information about the APIs being developed, the assumptions made and the technologies used.The salient classes from the API.The type of APIs currently available. Actual functions calls have not been described for sake of brevity.