http://www.dews.org.uk/ DELIVERING ENVIRONMENTAL WEB SERVICES (DEWS) Partners: The Met Office (Lead Partner), British Atmospheric Data Centre (BADC), British Maritime Technology (BMT), Environmental Systems Science Centre, University of Reading (ESSC), IBM, Lost Wax

The DEWS project has set itself challenging objectives to revolutionise the way in which users are able to work with high-volume, real-time environmental data and information. Web Services technology offers the only practical solution to developing a Service Oriented Architecture that can meet the requirements of many environmental applications. The project is examining scalability, interoperability and interface with legacy systems and software, reliability in an operational environment, the security and auditability of specific implementations.

DEWS aims to demonstrate this through two specific case study examples, in the Marine Safety and Health sectors. These examples are being used to show the powerful capabilities that Web Services can offer, to examine the benefits and shortfalls as they stand at present, and importantly, to promote early adoption by potential users of these technologies in an open architecture/open source environment. In addition the project also expects to deliver a range of new open source tools, Web Coverage, Feature and Map Services and OGC-compliant, XML-based data standards.

DEWS Portal:

A web portal to showcase the flexibility of servicing differing communities through portal environments and, to establish a single portal by which users can access the demonstration system via the Internet to interrogate health and marine data.

IBM Websphere Software:

IBM is providing industry leading middleware software that has allowed the team to build, deploy and run the DEWS technology showcase demonstrator in a proven, secure and flexible environment. Websphere enables users to connect via Web services and to view DEWS information sources from health and marine safety IT systems where the data is held in secure, high volume data base systems.

Information is presented through a single portal that is personalised at the time of log on, presenting content customised to the needs of the individual.

The BMT Platform is a modular application suite comprising three core modules:

SEAINFO:

Responsible for retrieving and processing data from the DEWS marine web coverage service. This incorporates a NetCDF extractor applied to a Postgres database.

SARIS:

Responsible for providing web processing services and web feature services to the SARIS Clients

SAR Clients:

Remote Rich Client application which consumer data from the SARIS system.

WFS:

Health information is exposed via a web feature service (WFS). The WFS exposes a OGC standards-compliant interface allowing any WFS client with appropriate privileges, such as the DEWS Portal, to request information.

The health information exchanged between server and client is encoded in a domain-specific 'Application Schema' that leverages the GML standard. This application schema forms an agreed 'contract' for exchanging content within an 'information community'. Geoserver's WFS implementation allows data in a private datastore conforming to a private 'persistence schema' to be mapped onto a published application schema, thus enabling a data provider to participate in an information community without needing to re-engineer their private datastores.

WCS:

GADS-WCS is the marine data server in the DEWS system, serving gridded ocean analysis and forecast data from the Met Office to BMT and other clients. It is based upon the OGC Web Coverage Service standard, with modifications for large data volumes and security and the server can be accessed at http://lovejoy.nerc-essc.ac.uk:8080/geoserver (see screenshot below)

Health Database:

The Health database contains the 'health forecast' data plus all the information required by the Health application to create the health forecast, including the real-time statistics being supplied by healthcare organisation and the Met Office's weather forecast. Because the WFS enables the mapping of the database schema onto a published application schema, the health database is decoupled from 'upstream' applications ensuring that external applications that rely on the health forecast will not be impacted by any changes to the health database.

Data Ingestor Health:

Ingestion utilities read and convert data provided by GP Out of Hours, NHS Direct, Ambulance Services and the Royal College of General Practitioners. These are received as formatted e-mail attachments, CSV files or XML files.

Data Ingestor Marine:

application to An ingestion process is provided as part of the DEWS facilitate the loading of NetCDF file data into the system. NetCDF files are transferred from a local file system and stored in binary large objects (blobs) in an Oracle database.

Terms and definitions:

OGC: Open Geospatial Consortium GML: OGC Geography Markup Language, v3.00 (OGC 03-023r4) UML: Unified Modeling Language XML: Extensible Markup Language WCS: OGC Web Coverage Service WFS: OGC Web Feature Service WMS: OGC Web Map Service 4-D: Four Dimensional (three space dimensions and time)

References:

1. GeoServer:http://docs.codehaus.org/display/GEOS/Multidimensional+WCS 2. NetCDF: http://www.unidata.ucar.edu/software/netcdf/ 3. OGC WCS Standard: http://www.opengeospatial.org/standards/wcs 4. OGC WFS Standard: http://www.opengeospatial.org/standards/wfs 5. OGC WMS Standard: http://www.opengeospatial.org/standards/wms 6. WebSphere: http://www-306.ibm.com/software/websphere/

Marine Database:

The smart datastore consists of an Oracle data cartridge, which is used to extend the functionality of the Oracle 10g database server such that it is able to deal with 4-D Gridded datasets. In particular it: • Introduces a database object type which mirrors the NetCDF file format; • Provides the means to efficiently query any metadata associated with the NetCDF database object types; • Provides the ability to manipulate and transform the database object by performing functions such as rotation and interpolation; • Provides an efficient mechanism to automatically load a NetCDF file and it's associated metadata.

The BADC has developed

Utility Services

which provide support for low level functions including: The

Security Service

ensures that the security policy as defined for a particular data stream is enforced throughout the platform. The security model is based on that of the NERC Data Grid.

The

Access Logging

in the platform services provides a fine grained audit trail of all transactions that occur

External Data Feeds:

Depersonalised data from two health service providers (GP Out-Of Hours and NHS Direct) are emailed daily to the system. The GP OOH data is based on the doctors’ call records whilst the NHS Direct data is based on the information gathered during a telephone consultation. They therefore necessarily contain different types of data. In future it is hoped that other sources of data – such as GPs and hospital admissions – will be sent for inclusion. In the marine stream, the UK Met Office provides gridded forecast and analysis model fields. A number of parameters are sent from both atmospheric and oceanographic models.