IVOA Interop, SL de El Escorial, Oct 2005 1

IVOA DAL - Madrid

DAL WG SummaryOctober 7, 2005

IVOA Interop, SL de El Escorial, Oct 2005 2

Simple Spectral Access (SSAP)

• Reviewed revised query interface– Introduced in Kyoto (May); at least one early implementation (JHU SS)– Agreement reaffirmed that basic query support time, spectral bandpass– add optional 'name', 'mtime' query parameters– unified specres, timeres, spatres parameters

• Reviewed spectral data model– "SED model" -> "spectral data model"– agreed to provide equivalent support for Spectrum, SED, TimeSeries– action on Semantics to define standard "targetClass" list

• Reviewed Characterization usage– minor discrepancies between SSA and DM versions– Not fully implemented (sampling, flux characterization)– will bring models into better agreement now that Char is stable

• UTYPE usage issue discovered– DAL usage is fixed tag; no tie to XML technology– form working group to resolve problem

• Updated schedule– Draft V1.0 for discussion Dec05– Advance to PR by May06

IVOA Interop, SL de El Escorial, Oct 2005 3

Spectral Line Access (SLAP)

• SLAP protocol presented, reviewed– consistent with other DAL interfaces– prototype implementations already exist

(VOSpec)– minor enhancements to query interface

suggested• e.g., provide way to query for forbidden lines only

• Updated schedule– SLAP data model, access interfaces at V0.1– will be released to DAL WG within a few days

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Simple Image Access (SIAP)

• Plans for SIA V1.1 upgrade briefly reviewed– will be based mainly on SSA (query, query response)– extension mechanism well tested, several prototype apps exist

• e.g., CGPS radio data cube data• Very powerful, will permit advanced capabilities of many sorts

– data staging still in technology investigation stage with GWS– Need for robust error handling, version control reaffirmed– Issue of one protocol or many discussed; need for object-specific

protocols reaffirmed• Protocol Issues

– consider error handling standards– how to step through large query responses– Coordinate these with GWS as they may be broader than DAL

• Updated schedule– goal to have draft V1.1 interface for discussion by Feb06

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Implementations

• Reference Implementations– Need for reference implementations discussed– important to define standards separately from

implementations– required to develop complex access protocols– required for service verification– link to Registry to record service compliance, availability

• Demonstrations– Detailed FOV using SIA extension mechanism, STC/XML, Aladin

support– WCS+graphics using query response, Aladin support

• VO-Client concept– required to provide high level functionality for analysis– Astrogrid, NVO implementations exist– example of using UTYPE for DM-based queries, query merging