ADEC Interoperability Technical Working Group Report

1. ADEC Interoperability Technical Working Group Report Tom McGlynn

2. Membership • IRSA: Bruce Berriman, John Goode • ADC: Kirk Borne, Brian Thomas • CXC: Arnold Rots • NED: Joe Mazzerella • ADS: Guenther Eichhorn • MAST: Tim Kimball • HEASARC: Tom McGlynn Tom McGlynn

3. Charter • Goal • The top level goal is to provide seamless (one stop shopping) access to all the NASA astrophysics catalog and data services, irrespective of where the information is located. • Charter Requirements • All services will be accessible via standard protocols • Access will be via the existing user interfaces • Results will appear consistent with the interface that initiated the request • Attribution of data to original site will be clearly stated Tom McGlynn

4. Current Interoperating Services • Many interoperating services are already in place at ADEC sites. E.g., • ADC links to HEASARC, IRSA and MAST archives • ADS links to all datasets associated with a given bibcode. • HEASARC links to CXC and MAST data and provides access to all VizieR tables. • IRSA suite of remotely accessible catalog and data services • MAST provides transparent access to HEASARC ROSAT and EUVE archives • NED links to multiple ADEC/non-ADEC data sources for many objects. NED name resolver used many places. • Astrobrowse services at CXC, MAST and HEASARC. • No general framework for interoperations • Limited capabilities • Incompleteness/inconsistency • Resource discovery is difficult • Fragile links Tom McGlynn

5. Summary of Activities • Telecons • January 18, 2002 • February 8, 2002 • Strawman design implementations • Temporary Web site • heasarc.gsfc.nasa.gov/itwg Tom McGlynn

6. Areas of Agreement • No generic mandates on user interfaces • Each site uses resources developed in this effort to present information appropriate to its users. • Layered approach to implementation • Stage 1: Links to data products and services • Stage 2: ‘Seamless’ services • Stage 3: ?? • Standardized publication of services • Monitoring of VO activities Tom McGlynn

7. Technical Issues • What kinds of links should be made? • What do we link to? • Home page, service forms, availability summaries, queries, data products • How do we mediate links? • Metadata or tables Tom McGlynn

8. Technical Issues • How are links/services published? • Machine versus human readable • Dynamic database or static pages • Syntax/standard to be used • How frequently updated • How is metadata about link included Tom McGlynn

9. Technical Issues • What is the vocabulary of linking? • Linking by characteristic • Links by position, time, object name • Other fields (exposure, observer, ...) • Table links, e.g., bibcode joins • Metadata vocabulary • Image/spectra • resolution, … • Where do we get metadata information from? Tom McGlynn

10. Technical Issues • Formats for metadata and queries • Usefulness of existing formats • Usefulness of emerging standards • Relationship to non ADEC institutions and efforts (CDS, VO) Tom McGlynn

11. Phase 1 Plan • Develop vocabulary for description of data center services (including access to data products). • Establish desired ancillary metadata for services. • Agree on protocol for publication of description of services. • Publish descriptions of services in agreed protocol. • Include links to described services/data in user interfaces. Tom McGlynn

12. Develop Linkage Vocabulary • How do we link? • Develop use cases • Describe current services • Name and provenance of the resource • How is the resource parametrized? • Position, time, name, bibcode, … • How is the resource accessed? • What is the format of the result? Tom McGlynn

13. Establish Ancillary Metadata • Why do we link? • Type of information returned • Product summary, catalog, image, spectra, home page, … • Wavelength regime • Optional metadata • Resolution, epoch range, volume estimators, ‘desirability’, ... • Dependencies/linkages to other services Tom McGlynn

14. Publication Protocol • Answer how and why questions • May use static product descriptor web pages at each site • Fixed location for each site • TBD XML? Format • Role of GLU -- if any. • Transition to UDDI/WSDL later? Tom McGlynn

15. Publish Service Descriptions • Multiple levels of description • Site • Data availability summaries • service data entry • service results • data products. • Most popular services first Tom McGlynn

16. Integrate into user interfaces • Site-based requirements • Not all services may be appropriate even when they are in principal queryable. • Review by ADEC Tom McGlynn

17. Schedule Issues • Dependent on resources allocated • Effort uncertain but anticipated at ~a few person-months per institution • Risk of impact on other activities • Coordination of diffuse resources is difficult Tom McGlynn

18. Schedule for Phase 1 • Six months to one year • Development of metadata • Initial vocabulary and ancillary metadata design • Agreement on publication format • Publication of services • Publication of popular services • Updates to vocabulary and ancillary metadata • Integration within existing interfaces • Integration within user interfaces • Additional service descriptions Tom McGlynn

19. Phase 2 ideas • More ‘seamless’ integration of systems. • Use of remote services as ‘database servers’. • Adoption of common machine readable format for results. • Coordination with VO activities • Use of Web as distributed file system for data products Tom McGlynn

20. ClassX: Classifying the High Energy Sky • Two year NASA AISR program to develop science prototype for Virtual Observatory. • Collaboration with ST ScI and CDS. • Classify high energy sources: • Discover and collect data on sources from existing services • Collate information into coherent dossiers. • Use information to classify sources. • Explore discovery, integration and metadata issues for VO. • Science goals: Samples of AGNs, early evolution of stars, analysis of XMM fields, ... A SkyView ROSAT field around TY Pyx showing the numerous serendipitous -- and largely unclassified -- WGACAT sources in that field. Tom McGlynn