Overview

VEGA has a consultation software and also exposes a web service to retrieve observation data.

Data extraction

The application has a special module to query the database through the HTTP port of the VegaObs Web Service.

Every observations with a non-empty dataStatus ('WaitProcessing', 'WaitOtherData', 'WaitPublication', 'Published') are imported as L0 data (see getObservationsVOTableByDataStatus)

The operation does not require special authentication and can be repeated for synchronization.

Data storage

The VegaObs data are imported in the database as regular OiDB granules.

Data mapping

The module is extracting data from observations in the VegaObs database.

The following rules are followed for mapping columns from the VegaObs database to the database schema of OiDB (based on the the ObsCore model):

• the rows are currently imported as part of a collection with id "vegaobs_import" (obs_collection)
• the dataPI name is put in the datapi column
• the value in ProgNumber is copied to the progid column
• the coordinates are resolved with Sesame Name Resolver from the value of the StarHD column
• the min and max wavelength (em_min, em_max) are set to the value of the Lambda column
• the observation start and stop times (t_min, t_max) are set to the value of the Date column converted to MJD

• the name of the facility used for the observation is set to 'MtW.CHARA' (from ever-growing list of facilities - ADS Web Services)
• the name of the instrument used for the observation is set to 'VEGA'

• the data URL (access_url) is left empty
• the total exposure time (t_exptime) is not filled
• the temporal resolution (t_resolution) is not filled
• the spectral resolving power (em_res_power) is not filled
• the channel count (nb_channel) is not filled
• the counts for VIS (nb_vis), VIS2 (nb_vis2) and T3 (nb_t3) measurement are not filled

• the granule is marked as proprietary (data_rights) with no release date

The type of the observed star (column TypeStar, 'TARGET or 'REFERENCE') is currently not mapped.

Usage

The operation is triggered from a button on the OiDB backoffice page starting the import process asynchronously.

The resulting granules are attached to the 'VegaObs Import' collection (obs_collection = vegaobs_import). The full collection is rebuilt and old granules dropped on a successful attempt at updating the data.

Notes

The instrument mode is derived from the columns of the database and the description of the instrument.

The database is designed to link observations with publication but this feature is mostly unused at the moment.