8.6
Web-based weather and a road-state briefing system for highway maintenance decision makers
Peter J. Trevelyan, The U.K. Met Office, Exeter, United Kingdom; and A. M. Radford
The Met Office currently relies heavily on visualisation and production systems that together form the production chain. For the sake of efficiency the systems are closely coupled and optimised for each specific type of product. As a consequence the production chain is inflexible and the “pull through” of recent scientific advances is difficult, time consuming and costly. This situation needs to be improved so that the increased capability due to advances in science can be quickly delivered directly to the customer in a way that is meaningful i.e. within the context of their specific requirements. It must also be done in such a way that it does not require the handling of obscure data formats and transport protocols. In order to address this problem the Met Office is re-designing the production process by moving towards a new architectural pattern i.e. “Service Oriented Architecture”. This will provide a sound architectural basis for defining a loosely coupled production chain based upon collaborating services. In order for these services to connect and communicate a new set of interface standards are needed and the OGC (Open Geospatial Consortium) specifications have been adopted and utilised by the Met Office. Much use is made of the OGC's “Geography Markup Language (GML)” that uses XML to express geospatial data and serves as a modelling language for geographic systems as well as an open interchange format for geo-spatially referenced data. The first real operational use of this architecture will be the delivery of a “route based” forecast for trial for the UK highways agency.
Recent improvements in the spatial resolution of NWP (Numerical Weather Prediction) models has meant that the Met Office's road surface temperature model (MORST) can now be run at a resolution of less than one kilometre. MORST provides a forecast of the road state i.e. forecast road pavement temperature and condition (e.g. wet, dry, frozen, snowy etc) giving a highly detailed picture of the environment along any route. The output from these models is combined with other information such as infrastructure (e.g. bridges, roads, underpasses etc) and real time and forecast weather to provide the decision maker with enough information to task the local authorities with activities such as snow clearance, gritting etc.
In order to combine all this information (not just overlay, but combine layers thematically) the SOA has been used to fuse a number of technologies e.g. GIS, Radar, MORST, geoprocessing, cartography and NWP, by exposing them as services. The client software is based on Adobe's Flex toolkit which is used to create a true rich internet client that is very effective at making use of the collaborating services and providing a very rich GUI (Graphical User Interface). This client software will be delivered to the end user ready for use in the 2007/2008 winter season.
This talk presents the design and development of the web-based applications and the foundational SOA used to host and expose the underpinning services such as ESRI's ArcGIS and the UK Met Office's SWIFT system. This talk will also report on the lessons learned from our experiences with the “Route Based Forecast” and in particular describe:-
• The architecture;
• The key foundation services;
• The design and building of the rich internet client;
• A description of how the XML (using GML) schemas of road and weather features were developed and served using a “Web Feature Service” (WFS).
• How well the OGC interfaces worked;
• The scalability of the S.O.A architecture;
• The ease in which a product could be changed without making changes to any application;
• A demonstration of the product;
• Future plans.
Session 8, Advances and Applications in Surface Transportation Weather (Continued)
Thursday, 24 January 2008, 11:00 AM-12:15 PM, 207
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