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. All observations with a non empty data status.

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

Data storage

Within the application, the retrieved data are saved to an XML database that is separated from the database of the other data that are extracted from OIFits files. It is planned to merge the two database schema soon.

The VegaObs data are now imported in the main database with the column mapping described below.

Data mapping

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

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

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 named "Vega Import" (obs_collection)
• the dataPI name is put in the datapi
• the value in ProgNumber is copied to the progid
• the coordinates are resolved with Sesame 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 is not filled

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

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. Also the data status field may not be always up to date.