Download Overview and Results so far

German Astrophysical Virtual
Observatory
Overview and Results So Far
W. Voges, G. Lemson, H.-M. Adorf
Now: N x M interfaces
USM 13-Feb-2004
Future: N + M interfaces
USM 13-Feb-2004
(GA)VO architecture
USM 13-Feb-2004
International Virtual Observatory Alliance
USM 13-Feb-2004
IVOA working groups
Registry
Data Access Layer
Data Modeling
VOQL/ADQL
VOTable
UCD
Grid and Web services
USM 13-Feb-2004
Standards and Protocols
IVOA exchange standards





Simple Cone Search (SCS)
Simple Image Access (SIA)
Simple Spectra Access (SSA)
VOTable
OpenSkyNode, VOQL/ADQL
General standards

HTTP, XML, SOAP, WSDL
USM 13-Feb-2004
Registry
USM 13-Feb-2004
SCS
USM 13-Feb-2004
Result
USM 13-Feb-2004
VOTable
USM 13-Feb-2004
Tools –
Aladin
USM 13-Feb-2004
IVOA::Experiments
Data Model
Protocols::Protocol
«key» -identifier : string
-documentationURL : string
-recipe
Experiment
«key» -identifier : string
1
ObjectList
TimeOrderedData
*
Protocols::InputDataType
*
-configuration
*
-inputData
-inputDataType
*
Configuration
-result
InputData
-type
1
Result
What? Why?
Observation
Quantity
Simulation
Domain model/ontology
as “Esparanto”
Archive meta-data repositories
VisibilityData
-protocol
Protocols::ConfigurationDescriptor
1
Image
-artifact
1
1
-subject
-configurationParameter
Products::PhysicalArtifact
«key» -locator : string
-description : string
ConfidenceIndication
1
*
-confidence
-observation
-observable
Subject
Protocols::Objective
*
*
-observable
1..*
-values
-variables
Protocols::Variable
-variable
ValueAssignment
«key» -name : string
-isIndependent : boolean
*
Uncertainty
1
-value
Measurement
1
Values::Quantity
1
-uncertainty
USM 13-Feb-2004
*
«key» -identifier : string
Classification
-value
Values::Classifier
1
Identification
-value
1
Values::Identifier
GAVO’s Pillars
Federation of datasets
Matching & Classification & Visualization
(NGSE)
Theoretical VO and Theory-Observation
Interface
Grid computing
USM 13-Feb-2004
Federation of Datasets
Towards a multi-wavelength view of
universe
Matching



Source extraction (P. Schuecker et al.)
Classification (GAVO/ClassX)
SED’s
ADQL/OpenSky Node
USM 13-Feb-2004
Federation of Datasets (cntd.)
Web services


Allow J2EE and .NET applications to
interact with each other
Based on standards + protocols
 HTTP + XML or SOAP + WSDL
Examples

MCMCS download manager
USM 13-Feb-2004
NGSE
(Next Generation Search Engine)
Download Manager

Retrieves data from multiple distributed databases
Matcher

Matches sources based on sky-position
(astronomical sources have no unique identifier)
Classifier

Uses multi-wavelength data for identification
purposes
Visualization Tool
USM 13-Feb-2004
Theory in the VO
Publication of simulations
Exposing theory services
Theory-observational interface

“Virtual telescope”, e.g. for proposal
preparation support
USM 13-Feb-2004
Grid computing
Working with Globus Toolkit
Looking into alternative technologies

SGE, EJBs
Gadget simulation running on joint MPE and
AIP workstation clusters
Interested in a good application

that would benefit from parallel distributed
computing:
 too large to run on a single computer, or
 require a quick turn around
USM 13-Feb-2004
GAVO Accomplishments
Publication of ROSAT datasets
Download Manager
Matcher
Documents


ADASS contributions
TVO White Paper
WIP


VOTable readers and writers
Service “adapters”
USM 13-Feb-2004
ROSAT BSC, FSC & Photons
VO-compatibility:


Simple cone search in
VOTable out
New features



Exposure times
Galactic & Cartesian coordinates
Healpix indices
USM 13-Feb-2004
MCMCS Download Manager
Tool …

… accesses registry at JHU
User …


… selects up to 70 distributed catalogues
… specifies one or more sky-locations
Tool …


… queries remote catalogues
… retrieves datasets (VOTables) for further
processing
USM 13-Feb-2004
MCMCS Download Manager
USM 13-Feb-2004
MCMCS Download Manager
USM 13-Feb-2004
Workflow
USM 13-Feb-2004
Matcher (on-going work)
Essential for data mining
Prototype features
 Performs “fuzzy” match between pairs of source lists
from different catalogues
 Computes probability of real match based on astrometric
uncertainties
Moving matcher into production use
 Currently exported to Canadian Virtual Observatory
 Feeding matches to ClassX classifier
Long-term goal: assemble an SED
USM 13-Feb-2004
Matcher (on-going work)
USM 13-Feb-2004
Classification (soon)
ClassX: international collaboration
Requires data from several large skysurveys
 X-ray: ROSAT (BSC + FSC)
 Optical: SDSS, USNO
 Infrared: 2MASS
 Radio: FIRST, NVSS, SUMSS
True multi-wavelength VO-application
USM 13-Feb-2004
Theory in the VO
TVO white paper
Formation of an IVOA special interest
group
USM 13-Feb-2004
Outlook
Emphasis on

3rd generation REST- or SOAP-based Web services
 Proxy/adapter services, e.g. to SDSS, CDS, NED, …
 “Virtual telescope” for proposal preparation support

4th generation “Grid” application: combination of
several Web services into one, e.g.





Upload of coordinate list to major datacenters
Combine match lists using “fuzzy” matcher
Construct quasi SED
Feed match candidates into remote ClassX classifier
Plan: offer as public service
USM 13-Feb-2004
Collaboration Models
Listen to scientists/end user requests
Support data publication
Implement new services

E.g. decision support tool for (observing or
funding) proposal preparation
USM 13-Feb-2004
How could we help?
Knowledge transfer


Publishing datasets in a VO-compatible
form
Establishing new services (e.g. wrappers
around legacy code)
 Offer expertise with Web and J2EE apps,
protocols and new standards
USM 13-Feb-2004
Questions
What do you expect from us?
What role do you see yourself in?

Scientist/end user or data provider?
What could you offer?
How can we collaborate?
USM 13-Feb-2004
Discussion
USM 13-Feb-2004