Observation Data Model Core Components
and its Implementation in the Table Access Protocol
Date:
10 May 2017 08:00:00
Publisher:
IVOA
Description:
This document defines the core components of the Observation data model
that are necessary to perform data discovery when querying data centers
for astronomical observations of interest. It exposes use-cases to be carried out,
explains the model and provides guidelines for its implementation as a data access
service based on the Table Access Protocol (TAP).
It aims at providing a simple model easy to understand and to implement by data
providers that wish to publish their data into the Virtual Observatory. This
interface integrates data modeling and data access aspects in a single service and
is named ObsTAP. It will be referenced as such in the IVOA registries.
In this document, the Observation Data Model Core Components (ObsCoreDM) defines
the core components of queryable metadata required for global discovery of
observational data. It is meant to allow a single query to be posed to TAP
services at multiple sites to perform global data discovery without having to
understand the details of the services present at each site. It defines a minimal
set of basic metadata and thus allows for a reasonable cost of implementation by
data providers. As with most of the VO Data Models, ObsCoreDM makes use of STC,
Utypes, Units and UCDs. The ObsCoreDM can be serialized as a VOTable. ObsCoreDM
can make reference to more complete data models such as Characterisation DM,
Spectrum DM or Simple Spectral Line Data Model (SSLDM). ObsCore shares a large set
of common concepts with DataSet Metadata Data Model (Cresitello-Dittmar et al. 2016)
which binds together most of the data model concepts from the above models in a
comprehensive and more general frame work. This current specification on the
contrary provides guidelines for implementing these concepts using the TAP protocol
and answering ADQL queries. It is dedicated to global discovery.
