2017-07-11 Observation Facility Meeting

Date

11 Jul 2017

Location

• Paris Observatory, Building B, 3rd floor
• Coffee and croissant at 9h30.

Attendees

• Baptiste Cecconi

• Tarek Al-Ubaidi

• Mireille Louys (CDS)
• Jérôme Berthier (IMCCE)
• Jonathan Normand (IMCCE)

Goals

• Observation Facility nomenclature

• VOFacility data model

• Convergence of Observation Facility name resolver (IMCCE) / observatory matrix (IWF) 

Documents and Links

• Local VESPA pages:
  • Observatory Facility Database
  • Merging Facility Lists
  • Existing List of Observatories and Spacecraft
• Presentations at IVOA meetings:
  • http://wiki.ivoa.net/internal/IVOA/InterOpMay2016-Semantics/Semantics-VOFacility-BC.pdf
  • http://wiki.ivoa.net/internal/IVOA/InteropMay2017-Semantics/Semantics-Facilities-BCecconi.pdf

Discussion items

General Presentation (Baptiste Cecconi)

• Notes on IMCCE work
  • Name resolver = https://api.ssodnet.imcce.fr/quaero/1/sso?q=cassini
    • Syntax : https://api.ssodnet.imcce.fr/quaero/1/sso?q= + name to search
  • Spacecraft list is ingested weekly from Celestrak
  • Based on ElasticSearch
  • Parent = primary object around with the spacecraft is orbiting
  • System = main gravitational system

• Notes on IWF work
  • Merging done by Tarek (scripts) and Manuel (runs and checks)
  • JSON formatted output, including all alternateNames as a list (with source, name and id from list)
  • Various merging paths:
    • direct match (name_listA = id_listB or name_listA = name_listB or id_listA = id_listB)
    • fuzzy match (added location match , ...)
    • inclusion match (compare partial parts of names)

• Next steps 
  • send example from IWF to IMCCE
  • identify and prioritize new lists to merge
  • implement "merge new lists in merged_list"
  • how to update information from updated lists
  • import into matrix of observatories ? 
  • how to proceed with webservices ? needed ? 
  • plan a meeting for final merge step ? 

Extra discussion with Mireille Louys

• Slides presented at LISA8 conference (Librarians)
  • Many use cases presented, including Instruments.
  • Need to link between nomenclature/aliases list with Registry.
  • EtherPad to discussed and describe needs: https://oasis.sandstorm.io/shared/ZpiQhYHptf7dEWXKSjmOVxGDkjEBvLbMA39m7CI5rZY/

Discussion on granularity / levels of description. Examples:

• SRN-NDA-Routine
  • SRN (Station de Radioastronomie de Nançay) = Observatory
  • NDA (Nançay Decameter Array) = Telescope
    => accurate location (mostly) + pointing 
  • Routine = Instrument
• Same for SNR-NDA-NewRoutine
• Cassini-RPWS-HFR
  • Mission = Cassini
  • Spacecraft = Cassini ou Cassini Orbiter => location 
  • Experience = RPWS (Radio Plasma Wave Science) (<=> Telescope) => pointing
  • Instrument = HFR (High Frequency Receiver)
• Cassini-VIMS
• Cassini-Huygens-DISR
• Voyager2-PRA-HB
  • Mission = Voyager
  • Spacecraft = Voyager 2
  • Experience = PRA (Planetary Radio Astronomy)
  • Instrument = HB (High Band) 
• LOFAR-LBA
  • Observatory = LOFAR = ILT (International LOFAR Telescope) => location of interferometer center of phase 
  • LOFAR station = each node of LOFAR interferometer => location of each node
  • Telescope / Instrument = LBA (Low Band Antenna array) or HBA (High Band Antenna array) for each LOFAR Station => coarse beam pointing 
  • Analog to digital conversion  = analog front-end
  • Instrument (imager ou spectrum) = software in central computing facility => pointing
• Same issues with CTA, SKA, VLA... 

What are the search criteria for resource identification in a discovery search from a scientist ?

• Name of the instrument ? (such as STIS on HST)
• Name of Instrument + InstrumentHost ? (such as VIRTIS/Rosetta or Cassini/Mag) => note the order can change between communities...

Brief exploration of NASA/PDS4 information model

Example of a context product for MAVEN (description of the instrument_host):

• URI = urn:nasa:pds:context:instrument_host:spacecraft.maven

• Registry link = https://pds.nasa.gov/services/registry-pds4/extrinsics/logicals/urn:nasa:pds:context:instrument_host:spacecraft.maven
  • Syntax is https://pds.nasa.gov/services/registry-pds4/extrinsics/logicals/ + logical_identifier 
• Other link from Browsable interface: https://starbase.jpl.nasa.gov/pds4/context-pds4/instrument_host/Product/PDS4_host_MAVEN_1.0.xml
  • Browsable interface:https://starbase.jpl.nasa.gov/pds4/context-pds4

NB: PDS4 is an implementation of OAIS standard.

NASA/PDS4 Information model is available here: https://pds.jpl.nasa.gov/pds4/doc/im/current/index_1800.html (version 1.8.0.0)

Internal_reference relations are listed here: https://pds.jpl.nasa.gov/pds4/doc/im/current/index_1800.html#attribute_pds_internal_reference_pds_reference_type

Action items