arXiv subjects

Norman Gray

Publications and source records attributed to Norman Gray.

At least 19 recordsLinked to original sources

arXiv2015

IVOA recommendation: Units in the VO

This document describes a recommended syntax for writing the string representation of unit labels ("VOUnits"). In addition, it describes a set of recognised and deprecated units, which is as far as possible consistent with other relevant standards (BIPM, ISO/IEC and the IAU). The intention is that units written to conform to this specification will likely also be parsable by other well-known parsers. To this end, we include machine-readable grammars for other units syntaxes.

astro-ph.IM↗

arXiv2015

Xoxa: a lightweight approach to normalizing and signing XML

Cryptographically signing XML, and normalizing it prior to signing, are forbiddingly intricate problems in the general case. This is largely because of the complexities of the XML Information Set. We can define a more aggressive normalization, which dispenses with distinctions and features which are unimportant in a large class of cases, and thus define a straightforwardly implementable and portable signature framework.

cs.CR↗

arXiv2015

Significant problems in FITS limit its use in modern astronomical research

The Flexible Image Transport System (FITS) standard has been a great boon to astronomy, allowing observatories, scientists and the public to exchange astronomical information easily. The FITS standard is, however, showing its age. Developed in the late 1970s the FITS authors made a number of implementation choices for the format that, while common at the time, are now seen to limit its utility with modern data. The authors of the FITS standard could not appreciate the challenges which we would be facing today in astronomical computing. Difficulties we now face include, but are not limited to, having to address the need to handle an expanded range of specialized data product types (data models), being more conducive to the networked exchange and storage of data, handling very large datasets and the need to capture significantly more complex metadata and data relationships. There are members of the community today who find some (or all) of these limitations unworkable, and have decided to move ahead with storing data in other formats. This reaction should be taken as a wakeup call to the FITS community to make changes in the FITS standard, or to see its usage fall. In this paper we detail some selected important problems which exist within the FITS standard today. It is not our intention to prescribe specific remedies to these issues; rather, we hope to call attention of the FITS and greater astronomical computing communities to these issues in the hopes that it will spur action to address them.

astro-ph.IM↗

arXiv2015

Learning from FITS: Limitations in use in modern astronomical research

The Flexible Image Transport System (FITS) standard has been a great boon to astronomy, allowing observatories, scientists and the public to exchange astronomical information easily. The FITS standard, however, is showing its age. Developed in the late 1970s, the FITS authors made a number of implementation choices that, while common at the time, are now seen to limit its utility with modern data. The authors of the FITS standard could not anticipate the challenges which we are facing today in astronomical computing. Difficulties we now face include, but are not limited to, addressing the need to handle an expanded range of specialized data product types (data models), being more conducive to the networked exchange and storage of data, handling very large datasets, and capturing significantly more complex metadata and data relationships. There are members of the community today who find some or all of these limitations unworkable, and have decided to move ahead with storing data in other formats. If this fragmentation continues, we risk abandoning the advantages of broad interoperability, and ready archivability, that the FITS format provides for astronomy. In this paper we detail some selected important problems which exist within the FITS standard today. These problems may provide insight into deeper underlying issues which reside in the format and we provide a discussion of some lessons learned. It is not our intention here to prescribe specific remedies to these issues; rather, it is to call attention of the FITS and greater astronomical computing communities to these problems in the hope that it will spur action to address them.

astro-ph.IM↗

arXiv2014

Learning from 25 years of the extensible N-Dimensional Data Format

The extensible N-Dimensional Data Format (NDF) was designed and developed in the late 1980s to provide a data model suitable for use in a variety of astronomy data processing applications supported by the UK Starlink Project. Starlink applications were used extensively, primarily in the UK astronomical community, and form the basis of a number of advanced data reduction pipelines today. This paper provides an overview of the historical drivers for the development of NDF and the lessons learned from using a defined hierarchical data model for many years in data reduction software, data pipelines and in data acquisition systems.

astro-ph.IM↗

arXiv2014

The Unified Astronomy Thesaurus

The Unified Astronomy Thesaurus (UAT) is an open, interoperable and community-supported thesaurus which unifies the existing divergent and isolated Astronomy & Astrophysics vocabularies into a single high-quality, freely-available open thesaurus formalizing astronomical concepts and their inter-relationships. The UAT builds upon the existing IAU Thesaurus with major contributions from the astronomy portions of the thesauri developed by the Institute of Physics Publishing, the American Institute of Physics, and SPIE. We describe the effort behind the creation of the UAT and the process through which we plan to maintain the document updated through broad community participation.

astro-ph.IM↗

arXiv2014

IVOA Recommendation: Simulation Data Model

In this document and the accompanying documents we describe a data model (Simulation Data Model) describing numerical computer simulations of astrophysical systems. The primary goal of this standard is to support discovery of simulations by describing those aspects of them that scientists might wish to query on, i.e. it is a model for meta-data describing simulations. This document does not propose a protocol for using this model. IVOA protocols are being developed and are supposed to use the model, either in its original form or in a form derived from the model proposed here, but more suited to the particular protocol. The SimDM has been developed in the IVOA Theory Interest Group with assistance of representatives of relevant working groups, in particular DM and Semantics.

astro-ph.IM↗

arXiv2013

Tagging and Linking Lecture Audio Recordings: Goals and Practice

Making and distributing audio recordings of lectures is cheap and technically straightforward, and these recordings represent an underexploited teaching resource. We explore the reasons why such recordings are not more used; we believe the barriers inhibiting such use should be easily overcome. Students can listen to a lecture they missed, or re-listen to a lecture at revision time, but their interaction is limited by the affordances of the replaying technology. Listening to lecture audio is generally solitary, linear, and disjoint from other available media. In this paper, we describe a tool we are developing at the University of Glasgow, which enriches students' interactions with lecture audio. We describe our experiments with this tool in session 2012--13. Fewer students used the tool than we expected would naturally do so, and we discuss some possible explanations for this.

physics.ed-ph↗

arXiv2012

Astronomy and Computing: a New Journal for the Astronomical Computing Community

We introduce \emph{Astronomy and Computing}, a new journal for the growing population of people working in the domain where astronomy overlaps with computer science and information technology. The journal aims to provide a new communication channel within that community, which is not well served by current journals, and to help secure recognition of its true importance within modern astronomy. In this inaugural editorial, we describe the rationale for creating the journal, outline its scope and ambitions, and seek input from the community in defining in detail how the journal should work towards its high-level goals.

astro-ph.IM↗

arXiv2012

DMP Planning for Big Science Projects

This report exists to provide high-level guidance for the strategic and engineering development of Data Management and Preservation plans for 'Big Science' data. Although the report's nominal audience is therefore rather narrow, we intend the document to be of use to other planners and data architects who wish to implement good practice in this area. For the purposes of this report, we presume that the reader is broadly persuaded (by external fiat if nothing else) of the need to preserve research data appropriately, and that they have both sophisticated technical support and the budget to support developments. The goal of the document is not to provide mechanically applicable recipes, but to allow the user to develop and lead a high-level plan which is appropriate to their organisation. Throughout, the report is informed where appropriate by the OAIS reference model.

astro-ph.IM↗

arXiv2012

Managing Research Data in Big Science

The project which led to this report was funded by JISC in 2010--2011 as part of its 'Managing Research Data' programme, to examine the way in which Big Science data is managed, and produce any recommendations which may be appropriate. Big science data is different: it comes in large volumes, and it is shared and exploited in ways which may differ from other disciplines. This project has explored these differences using as a case-study Gravitational Wave data generated by the LSC, and has produced recommendations intended to be useful variously to JISC, the funding council (STFC) and the LSC community. In Sect. 1 we define what we mean by 'big science', describe the overall data culture there, laying stress on how it necessarily or contingently differs from other disciplines. In Sect. 2 we discuss the benefits of a formal data-preservation strategy, and the cases for open data and for well-preserved data that follow from that. This leads to our recommendations that, in essence, funders should adopt rather light-touch prescriptions regarding data preservation planning: normal data management practice, in the areas under study, corresponds to notably good practice in most other areas, so that the only change we suggest is to make this planning more formal, which makes it more easily auditable, and more amenable to constructive criticism. In Sect. 3 we briefly discuss the LIGO data management plan, and pull together whatever information is available on the estimation of digital preservation costs. The report is informed, throughout, by the OAIS reference model for an open archive.

astro-ph.IM↗

arXiv2011

Why don't we already have an Integrated Framework for the Publication and Preservation of all Data Products?

Astronomy has long had a working network of archives supporting the curation of publications and data. The discipline has already created many of the features which perplex other areas of science: (1) data repositories: (supra)national institutes, dedicated to large projects; a culture of user-contributed data; practical experience of long-term data preservation; (2) dataset identifiers: the community has already piloted experiments, knows what can undermine these efforts, and is participating in the development of next-generation standards; (3) citation of datasets in papers: the community has an innovative and expanding infrastructure for the curation of data and bibliographic resources, and through them a community of author s and editors familiar with such electronic publication efforts; as well, it has experimented with next-generation web standards (e.g. the Semantic Web); (4) publisher buy-in: publishers in this area have been willing to innovate within the constraints of their commercial imperatives. What can possibly be missing? Why don't we have an integrated framework for the publication and preservation of all data products already? Are there technical barriers? We don't believe so. Are there cultural or commercial forces inhibiting this? We aren't aware of any. This Birds of a Feather session (BoF) attempted to identify existing barriers to the creation of such a framework, and attempted to identify the parties or groups which can contribute to the creation of a VO-powered data-publishing framework.

astro-ph.IM↗

arXiv2011

AstroDAbis: Annotations and Cross-Matches for Remote Catalogues

Astronomers are good at sharing data, but poorer at sharing knowledge. Almost all astronomical data ends up in open archives, and access to these is being simplified by the development of the global Virtual Observatory (VO). This is a great advance, but the fundamental problem remains that these archives contain only basic observational data, whereas all the astrophysical interpretation of that data -- which source is a quasar, which a low-mass star, and which an image artefact -- is contained in journal papers, with very little linkage back from the literature to the original data archives. It is therefore currently impossible for an astronomer to pose a query like "give me all sources in this data archive that have been identified as quasars" and this limits the effective exploitation of these archives, as the user of an archive has no direct means of taking advantage of the knowledge derived by its previous users. The AstroDAbis service aims to address this, in a prototype service enabling astronomers to record annotations and cross-identifications in the AstroDAbis service, annotating objects in other catalogues. We have deployed two interfaces to the annotations, namely one astronomy-specific one using the TAP protocol}, and a second exploiting generic Linked Open Data (LOD) and RDF techniques.

astro-ph.IM↗

arXiv2011

IVOA Recommendation: An IVOA Standard for Unified Content Descriptors Version 1.1

This document describes the current understanding of the IVOA controlled vocabulary for describing astronomical data quantities, called Unified Content Descriptors (UCDs). The present document defines a new standard (named UCD1+) improving the first generation of UCDs (hereafter UCD1). The basic idea is to adopt a new syntax and vocabulary requiring little effort for people to adapt softwares already using UCD1. This document also addresses the questions of maintenance and evolution of the UCD1+. Examples of use cases within the VO, and tools for using UCD1+ are also described.

astro-ph.IM↗

arXiv2011

IVOA Recommendation: Maintenance of the list of UCD words Version 1.20

According to what is stated in the IVOA Recommendation "An IVOA standard for Unified Content Descriptors", a procedural document should be created in order to maintain (add, change, suppress words) the standard list of UCD1+ words "The UCD1+ Controlled Vocabulary". This document describes the procedure to maintain the standard list of UCD1+ words.

astro-ph.IM↗

arXiv2011

IVOA Recommendation: The UCD1+ controlled vocabulary Version 1.23

This document describes the list of controlled terms used to build the Unified Content Descriptors, Version 1+ (UCD1+). The document describing the UCD1+ can be found at the URL: http://www.ivoa.net/Documents/latest/UCD.html. This document reviews the structure of the UCD1+ and presents the current vocabulary.

astro-ph.IM↗

arXiv2011

IVOA Recommendation: Vocabularies in the Virtual Observatory Version 1.19

This document specifies a standard format for vocabularies based on the W3C's Resource Description Framework (RDF) and Simple Knowledge Organization System (SKOS). By adopting a standard and simple format, the IVOA will permit different groups to create and maintain their own specialised vocabularies while letting the rest of the astronomical community access, use, and combine them. The use of current, open standards ensures that VO applications will be able to tap into resources of the growing semantic web. The document provides several examples of useful astronomical vocabularies.

astro-ph.IM↗

arXiv2011

IVOA Recommendation: Sky Event Reporting Metadata Version 2.0

VOEvent defines the content and meaning of a standard information packet for representing, transmitting, publishing and archiving information about a transient celestial event, with the implication that timely follow-up is of interest. The objective is to motivate the observation of targets-of-opportunity, to drive robotic telescopes, to trigger archive searches, and to alert the community. VOEvent is focused on the reporting of photon events, but events mediated by disparate phenomena such as neutrinos, gravitational waves, and solar or atmospheric particle bursts may also be reported. Structured data is used, rather than natural language, so that automated systems can effectively interpret VOEvent packets. Each packet may contain zero or more of the "who, what, where, when & how" of a detected event, but in addition, may contain a hypothesis (a "why") regarding the nature of the underlying physical cause of the event. Citations to previous VOEvents may be used to place each event in its correct context. Proper curation is encouraged throughout each event's life cycle from discovery through successive follow-ups. VOEvent packets gain persistent identifiers and are typically stored in databases reached via registries. VOEvent packets may therefore reference other packets in various ways. Packets are encouraged to be small and to be processed quickly. This standard does not define a transport layer or the design of clients, repositories, publishers or brokers; it does not cover policy issues such as who can publish, who can build a registry of events, who can subscribe to a particular registry, nor the intellectual property issues.

astro-ph.IM↗