IVOA Provenance data model: hints from the CTA Provenance prototype

We present the last developments on the IVOA Provenance data model, mainly based on the W3C PROV concept. In the context of the Cherenkov astronomy, the data processing stages imply both assumptions and comparison to dedicated simulations. As a consequence, Provenance information is crucial to the end user in order to interpret the high level data products. The Cherenkov Telescope Array (CTA), currently in preparation, is thus a perfect test case for the development of an IVOA standard on Provenance information. We describe general use-cases for the computational Provenance in the CTA production pipeline and explore the proposed W3C notations like PROV-N formats, as well as Provenance access solutions.Comment: 4 pages, 3 figures, to appear in ADASS XXV proceedings, edited by N. P. F. Lorente, & K. Shortridge (San Francisco: ASP), ASP Conf. Se

Implementation feedback of the IVOA Provenance data model

The IVOA Provenance Data model defines entities, agents and activities as container classes to describe the provenance of datasets, with the executed tasks and responsibilities attached to agents. It also provides a set of classes to describe the activities type and their configuration template, as well as the configuration applied effectively during the execution of a task. Here we highlight lessons learned in the implementation of the CDS ProvHiPS service distributing provenance metadata for the HST HiPS data collections, and for the HST archive original images used to produce the HiPS tiles. ProvHiPS is based on the ProvTAP protocol, the emerging TAP standard for distributing provenance metadata. ProvTAP queries may rapidly become very complex. Various graph representation strategies, including ad hoc solutions, triplestore and SQL CTE have been considered and are discussed shortly.Comment: 4 pages, to appear in proceedings of ADASS XXIX, ASP Conf. Serie

Radio Astronomy visibility data discovery and access using IVOA standards

Enhancing interoperable data access to radio data has become a science priority within the International Virtual Observatory Alliance (IVOA). This lead to the foundation of the IVOA Radio astronomy Interest Group. Several radio astronomers and project scientists enrolled in various projects (NRAO, ASKAP, LOFAR, JIVE, ALMA, SKA, INAF, NenuFAR, etc.) have joined. Together they are paving the way to a better integration of their services in the virtual observatory (VO) infrastructure and propose extension of IVOA standards to help achieving this goal. Calibrated radio datasets such as cubes, images, spectra and time series can already be searched and retrieved using the ObsCore/ObsTAP specification defined in the IVOA, or by data product-specific services like SIAv2, SODA, SSA and ConeSearch. However, properties of radio visibility data are not fully implemented in the VO landscape yet. We need specific features to refine data discovery and selection that are adapted to radio astronomers' need. In this context the VO team at the Centre de Donn\'{e}es astronomiques de Strasbourg (CDS) proposes to consider the ObsCore/ObsTAP specification and to establish cross-walks between the ObsCore and the existing Measurement Set (MS) metadata profile for data discovery of radio visibility data (VD). In order to account for the difference in granularity between radio VD datasets and science-ready datasets of the VO, the approach splits a MS data file into a list of datasets served by an ObsTAP service, thus enabling coarse grain discovery in the multi-wavelength context. Radio specific metadata such as number of antennae, frequency ranges, $uv$ plane coverage plots, frequency-phase and frequency-amplitude plots, primary and synthesized beams are also provided either by adding column metadata or by using the DataLink technique.Comment: 4 pages, 2 figures, ADASS XXX Conference Proceedings Nov 202

Organizing Standardisation of Astronomical Data Access: the DAL WG Current Experience

The tremendous amount of data available in astronomy at all wavelengths allows astronomers to make new science and to correlate an extremely wide range of phenomena. It is also a challenge for digital data management distribution and processing. Interoperable data access protocols as designed by the IVOA take a major place in this challenge. This contribution reviews the current trends of IVOA efforts in this context

IVOA Data Access Layer: Goals, Achievements and Current Trends

International audienceThe IVOA Data Access Layer (DAL) working group was created in 2002 to define protocols to homogenize data discovery, data description, data retrieval, and data access processes. We describe its history and status today, and look at current trends for future development of the DAL protocols

A Triplestore Implementation of the IVOA Provenance Data Model

The IVOA (International Virtual Observatory Alliance) has proposed a standard for capturing the provenance metadata in the production and distribution of astronomical data. We present an implementation in a triplestore for the provenance information recorded for a collection of astronomical images. The ontology applied is derived from PROV-O from the W3C and from the IVOA Provenance data model. SPARQL queries based on the data model concepts allow to select datasets on a wide range of provenance properties and have proven to be efficient in the triplestore representation. The data model of the SIMBAD CDS database has also been tested, and turned out to scale very efficiently in the triplestore strategy as well