This topic aims to describe the specification from a technical point of view.

1.3 Granularity

The following discussion apply to data extraction from individual OIFits files.

Subgrouping must be done in the following order : target(OI_TARGET), instrument(OI_WAVELENGTH), night (OI_DATA rows)

Group by targets

Function: extract a list of targets
Inputs: OI_TARGET table / coords, coords+name, name
Outputs: List of targets (TargetUUIDs)
with CatalogIDs (HD HIP TBD1 TBD2)

Warning: target names are case sensitive

Use cases

• target name resolved
  • invalids
    • wrong coordinates vs simbad resolution
    • ambiguity after resolution : more than one result
• target name unresolved
  • invalids
    • 0 0 as given coords
• valids
  • duplicated targets : distinct name & same coords, approximate coordinates (which radius ?)

Impact

• oitools : add derived columns in OI_TARGET (TargetUUID + CatalogIDs)
• jmcs :
  • manage coords with epoch = J2000
  • resolve target names with simbad (catalog)
• oiexplorer-core
  • compute uuid (using coords?) (cf oid simbad)
  • compute new coordinates columns from simbad (deg J2000) (save a timestamp for the resolution, useful when running resolution later)
• oidb
  • provide a proxy to retrieve target uuid replacing simbad above for target resolution

Examples

Questions

• which additional information should be retrieved by simbad resolver ?

Group by instrument mode

Function: retrieve instrument modes
Inputs: OI_WAVELENGTH tables : INSNAME + EFF_WAVE_min/max + NB_EFF_WAVE + EFF_BAND
knowledge instrument_mode database
Outputs: List of instrument modes

Do not presume that every data are sorted properly in OIFits files when searching for min/max values.

Use cases

• same data with epsilon values should retrieve the same instrument mode (may feed INSNAME aliases)

Impact

• oitools : add derived column (InsModeID for each OI_DATA or one per data row?)
• oiexplorer-core : compute instrument signature (insname, wavelengths, resolution)
• oidb :
  • use instrument signature to select instrument mode
  • insname aliases, knowledge database (aspro-conf)
  • instrument configurations

Examples

Questions:

• how to handle data for unknown instrument ?
• how to store an instrument_mode (single string, fields concatenation...)
• How to solve ambiguity for MIDI (and MATISSE) between HIGH_SENS and SCI_PHOT ?

Group by nights

Function: split by observation nights
Inputs: OI_DATA tables : (DATE-OBS + TIME ) or (MJD), ARRNAME
OI_ARRAY tables
Outputs: List of observation nights

Use cases

• handle oifits without OI_ARRAY

Impact

• jmal : date, coords
• oitools : add derived column (NightID for each data line)
• oiexplorer-core : computing NightID

Examples

General

• oiexplorer-core must provide for every table row : the targetId, nightId, targetUuid
• do we have to refresh/compare data retrieved by simbad