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Date

Attendees

Goals

  • SLAC-IPAC meeting to discuss metaServ 

Discussion items

TimeItemWhoNotes

metaserv v1all
  • Tatiana Goldina expressed concerns that the current meatserv V1 does not satisfy SUIT needs to get information to build the query search form. Prototype metaserv allows SUIT to get a list of databases, but it's not possible to tell which database has science data, which tables are catalogs, "image metadata", or "forced sources" (used in light curve queries). SUIT needs to know which columns contain object, filter, ra and dec (corners ra and dec for images). We can aim for using “ucd” attribute to identify some of this information, but “ucd” is not always available and several fields might have the same “ucd”, like “pos.eq.ra”. How do we tell which column contains ra for the center of the image and which columns are for the corners? 
  • Brian Van Klaveren is working on implementing VO RegTAP (IVOA Registry Relational Schema) to facilitate data discovery, using VOResource.
  • For images, CAOM will be used to describe image metadata
  • UCD will be used to describe column data, but it might not be sufficient. UType will be explored for LSST specific information, i.e.
  • Question: which team is responsible to define UCD for each data item, pipeline team?
  • Todo: for L3 data ingest into the database, requirement/guidelines for users to provide UCD, mapping the user data into the LSST type so LSP could provide better tool/service.

future topics
  • sync SUIT expectation and DAX implementation plan

Use case from SUIT:

SUIT needs to provide a capability for users to browse all the possible metadata so users can decide what they want to explore further. The following API is needed to support this.


  1. SUIT needs to get all the databases (science, EFDs) to allow users to select and browse what is available:
    • DB name, 
    • type (does it have engineering data, catalogs, image metadata, multiepoch photometry table to obtain light curves?) 
    • description, 
    • possible link to the formal document about this DB
    • we also need to know the name of multiepoch photometry table, which contains the single-exposure measurements for every deep detection, 
      for example 'Science_Ccd_Exposure' for SDSS, 'allwise_p3as_mep' for WISE. This is assuming there is one such table per database/schema. 
  2. For each DB, SUIT needs to get a list of tables in the DB:
    • Table name, 
    • type (image metadata, catalog - source/forced source, EFD-related), 
    • description, 
    • possible link to the formal document about this table
    • when a table has object id, what is the name of multi-epoch table to get light curve queries for this object
  3. For each table, SUIT needs to get the following information for each column of the table:
    • UID (to identify columns that hold ra and dec, filter band, object id, image corners)
    • UType (extra info like the 4 corners of an image, ...), 
    • name,
    • description,
    • unit,
    • data type
    • relationship with columns in other table ( objectID in object table to objectID in source table)
      unless this relationship can be determined using UCDs

Since all users will login to the system, the permission of access level will be controlled by User Authorization system. 

Action items

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