Observation Data Model Core Components, its Implementation in the Table Access Protocol Version 1.0

Abstract

This document defines the core components of the Observation data model that are necessary to perform data discovery when querying data centers for observations of interest. It exposes usecases 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 ObsTAP -2 -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. There will be a separate document to cover the full Observation data model. 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. The combination of the ObsCoreDM with TAP is referred to as an ObsTAP service. 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 ObsProvDM (the Observation Provenance Data Model, to come), Characterisation DM, Spectrum DM or Simple Spectral Line Data Model (SSLDM). Status of this documentThis document has been produced by the IVOA Data Model (DM) working group, in coordination with partners involved in the definition of data access protocols (DAL) and of the ADQL language. It describes the core components of the Observation data model and the metadata to be attached to an astronomical observation, and contains a guide for implementing this model within the Table Access Protocol (TAP) framework. Due to the DM and DAL aspects of this document, this will circulate and be reviewed by both Working Groups. The document content has been worked out as working draft in a previous stage (2009)(2010) and is now proposed for IVOA recommendation.A list of current IVOA Recommendations and other technical documents can be found at http://www.ivoa.net/Documents/ Acknowledgements This work has been partly funded by Euro-VO AIDA project that we acknowledge here. SSC XMM Catalog service supported the implementation of the SAADA version of ObsTAP at Strasbourg Observatory. The US-VAO project contributed to developing this specification and prototyping the use of ObsTAP in the VAO portal. The CANFAR project also contributed for the reference implementation of ObsTAP at CADC, Victoria.ObsTAP -3 -

Evolution of Data Formats in Very-High-Energy Gamma-Ray Astronomy

“…The recent efforts reviewed in this issue successfully employing GADF-compliant data and open-source analysis tools will surely foster their usage for further scientific projects. The GADF does not represent an isolated effort and aims at maintaining compatibility with other established standards in high-energy astronomy, such as the OGIP (on which the GADF largely draws), or those used for high-level products within the virtual observatory [49]. Promoting the use of opensource analysis tools, as well as common open data formats will distinguish high-energy astrophysics in the future as one of the few branches of modern science unconcerned by the reproducibility dilemma affecting many other disciplines [50].…”

Evolution of Data Formats in Very-High-Energy Gamma-ray Astronomy

“…The recent efforts reviewed in this issue successfully employing GADF-compliant data and open-source analysis tools will surely foster their usage for further scientific projects. The GADF does not represent an isolated effort and aims at maintaining compatibility with other established standards in high-energy astronomy, like the OGIP (on which the GADF largely draws), or those used for high-level products within the Virtual Observatory [49]. Promoting the use of open-source analysis tools as well as common open data formats will distinguish high-energy astrophysics in the future as one of the few branches of modern science unconcerned by the reproducibility dilemma affecting many other disciplines [50].…”

TAP and the Data Models

“…The work around strategy is to propose one specific standard per model. This has been done first for ObsTAP (Tody et al 2011) which flattens the ObsCore model on one table. This is also the case for ProvTAP 4 which proposes a relational view for Provenance (Servillat et al 2020) data.…”