MOLES3: implementing an ISO standards driven data catalogue

ISO19156 Observations and Measurements (O&M) provides a standardised framework for organising information about the collection of information about the environment. Here we describe the implementation of a specialisation of O&M for environmental data, the Metadata Objects for Linking Environmental Sciences (MOLES3). MOLES3 provides support for organising information about data, and for user navigation around data holdings. The implementation described here, “CEDA-MOLES”, also supports data management functions for the Centre for Environmental Data Archival, CEDA. The previous iteration of MOLES (MOLES2) saw active use over five years, being replaced by CEDA-MOLES in late 2014. During that period important lessons were learnt both about the information needed, as well as how to design and maintain the necessary information systems. In this paper we review the problems encountered in MOLES2; how and why CEDA-MOLES was developed and engineered; the migration of information holdings from MOLES2 to CEDA-MOLES; and, finally, provide an early assessment of MOLES3 (as implemented in CEDA-MOLES) and its limitations. Key drivers for the MOLES3 development included the necessity for improved data provenance, for further structured information to support ISO19115 discovery metadata export (for EU INSPIRE compliance), and to provide appropriate fixed landing pages for Digital Object Identifiers (DOIs) in the presence of evolving datasets. Key lessons learned included the importance of minimising information structure in free text fields, and the necessity to support as much agility in the information infrastructure as possible without compromising on maintainability both by those using the systems internally and externally (e.g. citing in to the information infrastructure), and those responsible for the systems themselves. The migration itself needed to ensure continuity of service and traceability of archived assets

Implementation of UML Schema to RDBM

Numerous disciplines require information concerning phenomena implicitly or explicitly associated with a location relative to the Earth. Disciplines using Geographic Information (GI) in particular are those within the earth and physical sciences, and increasingly those within social science and medical fields. Therefore geographic datasets are increasingly being shared, exchanged and frequently re-purposed for uses beynd their original intended use. The ISO Technical Committee 211 (ISO/TC 211) together with Open Geospatial Consortium (OGC) provide a series of standards and guidelines for developing application schemas which should: a) capture relevant conceptual aspects of the data involved; b) be sufficient to satisfy previously defined use-cases of a specific or cross-domain concerns. In addition, the HollowWorld technology offers an accessible and industry-standardised methodology for creating and editing Application Schema UML models which conform to international standards for interoperable GI [2]. We present a technology which seamlessly transforms an Application Schema UML model to a relational database model (RDBM). This technology, using the same UML information model, complements the XML transformation of an information model produced by the FullMoon tool [2]. RDBMs exist to enable searching within a data collection, a process that has, over the decades, been heavily optimized. Moreover, modern non-relational DB [3] flavours (MongoDB, Cassandra, NewSQL) are still in their infancy with associated disadvantages for ease of adoption, software reliability, etc. A UML schema, or better its XMI description, has, in contrast, an almost natural mapping/transformation to an XSD schema and ISO19136 with well known applications, e.g. Fullmoon or Shape Change, supporting this approach. However, describing geographic information within a widely accepted XML-encoded vendor-neutral format such as GML may not be the best option for persisting or searching operations. Within a full model-driven approach the UML should remain at the centre of any implementation claiming to represent the model itself. In this context, a UML -> XSD -> RDBM transformation is not possible because the both the XSD and RDBM, and even an OWL implementation, have the same goal: to represent the same model. In a typical scenario an ingested XML document is separated into core and ancillary data: the core data map to a set of relational tables, the ancillary to a single XML-type field. This approach works well when the core data are a fraction of the whole document, and even better if the main aim of the RDBM is not to simply return other XML objects

The ESPAS e-infrastructure: Access to data from near-Earth space

ESPAS, the ‘‘near-Earth space data infrastructure for e-science ” is a data e-infrastructure facilitating discovery and access to obser- vations, ground-based and space borne, and to model predictions of the near-Earth space environment, a region extending from the Earth’s atmosphere up to the outer radiation belts. ESPAS provides access to metadata and/or data from an extended network of data providers distributed globally. The interoperability of the heterogeneous data collections is achieved with the adoption and adaption of the ESPAS data model which is built entirely on ISO 19100 series geographic information standards. The ESPAS data portal manages a vocabulary of space physics keywords that can be used to narrow down data searches to observations of specific physical content. Such content-targeted search is an ESPAS innovation provided in addition to the commonly practiced data selection by time, location, and instrument. The article presents an overview of the architectural design of the ESPAS system, of its data model and ontology, and of interoperable services that allow the discovery, access and download of registered data. Emphasis is given to the standardization, and expandability concepts which represent also the main elements that support the building of long-term sustainability activities of the ESPAS e-infrastructure