The Climate Science Modelling Language (CSML) was originally developed as part of the NERC Data Grid (NDG) project in the UK. It was one of the first Geography Markup Language (GML) application schemas describing complex feature types for the metocean domain. CSML feature types can be used to describe typical climate products such as model runs or atmospheric profiles. CSML has been successfully used within NDG to provide harmonised access to a number of different data sources. For example, meteorological observations held in heterogeneous databases by the British Atmospheric Data Centre (BADC) and Centre for Ecology and Hydrology (CEH) were served uniformly as CSML features via Web Feature Service. CSML has now been substantially revised to harmonise it with the latest developments in OGC and ISO conceptual modelling for geographic information. In particular, CSML is now aligned with the near-final ISO 19156 Observations & Measurements (O&M) standard. CSML combines the O&M concept of ’sampling features’ together with an observation result based on the coverage model (ISO 19123). This general pattern is specialised for particular data types of interest, classified on the basis of sampling geometry and topology. In parallel work, the OGC Met Ocean Domain Working Group has established a conceptual modelling ac- tivity. This is a cross-organisational effort aimed at reaching consensus on a common core data model that could be re-used in a number of met-related application areas: operational meteorology, aviation meteorology, climate studies, and the research community. It is significant to note that this group has also identified sampling geometry and topology as a key classification axis for data types. Using the Model Driven Architecture (MDA) approach as adopted by INSPIRE we demonstrate how the CSML application schema is derived from a formal UML conceptual model based on the ISO TC211 framework. By employing MDA tools which map consistently between UML and GML we can treat the formal UML model as the primary governed artefact and automatically produce the GML schema as a secondary output. Finally we describe how increased convergence between CSML and Scientific Feature Types in the Unidata Commmon Data Model may assist with bridging the implementation gap between OGC/ISO services and the CF-NetCDF binary data management community. This improved agreement at the conceptual (feature type) level is important to enable better interoperability at the data exchange and service levels.

The CEDA OGC Web Services framework (COWS) emphasises rapid service development by providing a lightweight layer of OGC web service logic on top of Pylons, a mature web application framework for the Python language. This approach gives developers a flexible web service development environment without compromising access to the full range of web application tools and patterns: Model-View-Controller paradigm, XML templating, Object-Relational-Mapper integration and authentication/authorization. We have found this approach useful for exploring evolving standards and implementing protocol extensions to meet the requirements of operational deployments. This paper outlines how COWS is being used to implement customised WMS, WCS, WFS and WPS ser- vices in a variety of web applications from experimental prototypes to load-balanced cluster deployments serving 10-100 simultaneous users. In particular we will cover 1) The use of Climate Science Modeling Language (CSML) in complex-feature aware WMS, WCS and WFS services, 2) Extending WMS to support applications with features specific to earth system science and 3) A cluster-enabled Web Processing Service (WPS) supporting asynchronous data processing. The COWS WPS underpins all backend services in the UK Climate Projections User Interface where users can extract, plot and further process outputs from a multi-dimensional probabilistic climate model dataset. The COWS WPS supports cluster job execution, result caching, execution time estimation and user management. The COWS WMS and WCS components drive the project-specific NCEO and QESDI portals developed by the British Atmospheric Data Centre. These portals use CSML as a backend description format and implement features such as multiple WMS layer dimensions and climatology axes that are beyond the scope of general purpose GIS tools and yet vital for atmospheric science applications.

CEDA (Centre for Environmental Data Archival) based at STFC Rutherford Appleton Laboratory is host to the BADC (British Atmospheric Data Centre) and NEODC (NERC Earth Observation Data Centre) with data holdings of over half a Petabyte. In the coming months this figure is set to increase by over one Petabyte through the BADC’s role as one of three data centres to host the CMIP5 (Coupled Model Intercomparison Project Phase 5) core archive of climate model data. Quite apart from the problem of managing the storage of such large volumes there is the challenge of collating the data together from the modelling centres around the world and enabling access to these data for the user community. An infrastructure to support this is being developed under the US Earth System Grid (ESG) and related projects bringing together participating organisations together in a federation. The ESG architecture defines Gateways, the web interfaces that enable users to access data and data serving applications organised into Data Nodes. The BADC has been working in collaboration with US Earth System Grid team and other partners to develop a security system to restrict access to data. This provides single sign-on via both OpenID and PKI based means and uses role based authorisation facilitated by SAML and OpenID based interfaces for attribute retrieval. This presentation will provide an overview of the access control architecture and look at how this has been implemented for CEDA. CEDA has developed an expertise in data access and information services over several years through a number of projects to develop and enhance these capabilities. Participation in CMIP5 comes at a time when a number of other software development activities are coming to fruition. New services are in the process of being deployed alongside services making up the system for ESG. The security system must apply access control across this heterogeneous environment of different data services and technologies. One strand of the development efforts within CEDA has been the NDG (NERC Datagrid) Security system. This system has been extended to interoperate with ESG, greatly assisted by the standards based approach adopted for the ESG security architecture. Drawing from experience from previous projects the decision was taken to refactor the NDG Security software into a component based architecture to enable a separation of concerns between access control and the functionality of a given application being protected. Such an approach is only possible through a generic interface. At CEDA, this has been realised in the Python programming language using the WSGI (Web Server Gateway Interface) specification. A parallel Java filter based implementation is also under development with our US partners for use with the THREDDS Data Server. Using such technologies applications and middleware can be assembled into custom configurations to meet different requirements. In the case of access control, NDG Security middleware can be layered over the top of existing applications without the need to modify them. A RESTful approach to the application of authorisation policy has been key in this approach. We explore the practical implementation of such a scheme alongside the application of the ESG security architecture to CEDA’s OGC web services implementation COWS.

This short paper outlines the key components of the NERC DataGrid: a discovery service, a vocabulary service and a software stack deployed both centrally to provide a data discovery portal, and at data providers to provide local portals and data and metadata services.

Much consideration is rightly given to the design of metadata models to describe data. At the other end of the data-delivery spectrum much thought has also been given to the design of geospatial delivery interfaces such as the Open Geospatial Consortium standards, Web Coverage Service (WCS), Web Map Server and Web Feature Service (WFS). Our recent experience with the Climate Science Modelling Language shows that an implementation gap exists where many challenges remain unsolved. To bridge this gap requires transposing information and data from one world view of geospatial climate data to another. Some of the issues include: the loss of information in mapping to a common information model, the need to create ‘views’ onto file-based storage, and the need to map onto an appropriate delivery interface (as with the choice between WFS and WCS for feature types with coverage-valued properties). Here we summarise the approaches we have taken in facing up to these problems.

MOTIIVE (Marine Overlays on Topography for annex II Valuation and Exploitation) is a project funded as a Specific Support Action (SSA) under the European Commission Framework Programme 6 (FP6) Aeronautics and Space Programme. The project started in September 2005 and finished in October 2007. The objective of MOTIIVE was to examine the methodology and cost benefit of using non-proprietary data standards. Specifically it considered the harmonisation requirements between the INSPIRE data component ‘elevation’ (terrestrial, bathymetric and coastal) and INSPIRE marine thematic data for ‘sea regions’, ‘oceanic spatial features’ and ‘coastal zone management areas’. This was examined in context of the requirements for interoperable information systems as required to realise the objectives of GMES for ‘global services’. The work draws particular conclusions on the realisation of Feature Types (ISO 19109) and Feature Type Catalogues (ISO 19110) in this respect. More information on MOTIIVE can be found at www.motiive.net.

The Climate Science Modelling Language (CSML) has been developed by the NERC DataGrid (NDG) project as a standards-based data model and XML markup for describing and constructing climate science datasets. It uses conceptual models from emerging standards in GIS to define a number of feature types, and adopts schemas of the Geography Markup Language (GML) where possible for encoding. A prototype deployment of CSML is being trialled across the curated archives of the British Atmospheric and Oceanographic Data Centres. These data include a wide range of data types – both observational and model – and heterogeneous file-based storage systems. CSML provides a semantic abstraction layer for data files, and is exposed through higher level data delivery services. In NDG these will include file instantiation services (for formats of choice) and the web services of the Open Geospatial Consortium (OGC).