Figure 1 Some examples of data displays from the Wind Energy Community
Architecture Increases Availability of Atmospheric Data and Models: Demonstration in Beijing
Open Geospatial Consortium, Inc.
Improving knowledge of the atmosphere is essential for achieving all nine of the “societal benefits” intended by the 61 countries and 40 international organizations who are bringing together their existing and new Earth observation hardware and software systems to create the Global Earth Observation “System of Systems” (GEOSS). To support efficient decision making, the diverse systems participating in GEOSS will interoperate through published, free, universally adopted interface and encoding standards.
To demonstrate the value of GEOSS, IEEE organized a series of workshops. The May 22, 2006 workshop at the International Sympo-sium on Future Intelligent Earth Observing Satellites (FIEOS’06) in Beijing, China, titled “The User and GEOSS Architecture III – Applica-tions for the Asia Pacific,” focused on wind energy and natural resource management. Dr. Jinsoo You and Dr. Konstantin Nurutdinov of the Centre for Geospatial Science, University of Nottingham, U.K. organized a demonstration to support the workshop theme. The demonstra-tion showed how the OGC’s standards are consistent with the open architecture of GEOSS. Eighteen organizations from six countries par-ticipated in the demonstration.
The demonstration scenario answered this question: Where are the suitable wind farm sites? Through collaboration with the GEOSS Wind En-ergy Community of Practice and other wind energy experts, the scenario focused on prospecting for potential locations and subsequent micrositing of a wind farm. The collaboration was important in considering the variety of relevant data, services, and models (Figure 1).
|Figure 2 A typical search operation for wind resource data (NASA — Earth-Sun System Gateway) |
|Figure 3 Global Wind Model outputs access using WCS (NOAA/NCDC, Unidata/UCAR, and Washington University)|
This demonstration postulated a hypothetical policy and resource manager to show how different data sets, at locations around the globe, can be discovered and gathered by a single customer. This flexibility is possible because the data sets adhere to a common set of standards and the customer uses tools that understand the protocols. (See sidebar on OGC Web Services, page 36.) The objective was real-time on-demand analysis of historical models and in-situ observational data for analysis leading to wind tower placement decisions.
The first stage of the demo involved searching for suitable data registered in Web-based catalogs that implement the CSW specifica-tion (Figure 2).
The scenario then involved a sequence of discovery and access operations, beginning with lower-resolution global wind data services and proceeding to high-resolution wind data services for the likely sites.
To assess the potential wind farm locations in a region, a significant wind data set was made available from NOAA’s National Operational Model Archive and Distribution System (NOMADS). Two years of National Weather Service Global Forecast System (GFS) numerical model monthly mean wind data were available using the OGC WCS on NOMADS Servers. Based on a regional analysis of China, the Hainan Dao (Hainan Island) was selected for a more detailed evaluation (Figure 3).
|Figure 4 Partial map layers of processed wind data through WMS (NRCan/GeoConnections and Environment Canada)|
Several key components in the demonstration were provided by a separate OGC project: “Geo-interface for Air, Land, Earth, Oceans NetCDF Interoperability Experiment” (GALEON). Under the leadership of UCAR (University Corporation for Atmospheric Research, which carries out its mission through management of the National Center for Atmospheric Research-NCAR), GALEON aims to improve interop-erability between “fluid earth systems” and other geospatial technologies.
Based on the regional analysis, a catalog search with a more focused area of interest (Hainan Dao) resulted in the discovery of network-accessible web services with both higher resolution data and additional observation types relevant to the wind farm siting analysis.
The analyst categorized the wind speed data, selected certain wind speed ranges, and displayed the results (Figures 4, 5 and 6).
WCS with 3D modeling came into play with wind speed data. Wind speed ranges were selected and the results displayed. Areas of candi-date sites were calculated. Candidate wind farm sites were selected and measurements were made of the distance between those sites and the nearest roads and transmission lines.
By using geospatial standards developed for any type of data and service with location as an organizing parameter, the integration of atmos-pheric data with traditional Geographic Information System (GIS) data is simple (Figure 7). The siting of a wind farm must consider which way the wind blows, but the final decision is based on economic and social factors. The integration of features from a GIS database with wind data from atmospheric databases and models was a significant point of the demonstration.
This demonstration showed what can be accomplished in a distributed computing environment by using open standards. The key in-formation was accessed using OGC Web services standards. The rapid data discovery and access reduces the time to conduct an analysis by roughly a factor of four. Using distributed services increases the types of data that are available. (While not part of this demonstration, digital rights management is an element of the OGC Web Services architecture.)
Charlotte Hasager of the Wind Energy Department at Denmark’s Risoe National Laboratory said, “Use of distributed Web services is clearly a very good option to be further exploited in wind energy. In China the aim to use satellite imagery and database information for wind resource mapping is higher than anywhere else I have seen.”
|Figure 5 10-m above-ground average wind speed (processed by IMAA/CNR and University of Nottingham)|
Additional demonstrations of the GEOSS Architecture principles, such as the use of open standards for interoperability, will be conducted throughout the remainder of 2006. These demonstrations will be part of future GEOSS User Workshops led by IEEE.
The agreement within the GEOSS community to use consensus-derived open standards to accomplish interoperability reflects two trends. One is the general trend towards such standards within the larger Information Technology world.
The other trend is the growing perception among policy makers and ordinary people that climate change, weather disasters, and air pollution deserve our immediate attention. Few programs for understanding these problems hold as much promise as GEOSS.
||Note: Figures are from a presentation titled, “Implementing the GEOSS Architecture Using Open Standards — GEOSS Demonstrator using OGC Specifications,” given at The User and GEOSS Architecture Workshop, 22-23 May 2006. Authors: Dr. Jinsoo You, Dr. Konstantin Nurutdinov, Prof. Mike Jackson of the Centre for Geospatial Science, University of Nottingham, www.nottingham.ac.uk/cgs. For information about workshops, see www.grss-ieee.org/menu.taf?menu=GEOSS&detail=GEOSSWorkshops.|
|Figure 6 Publishing processed wind data through WMS (processed by ITT, formerly RSI)
|Figure 7 Feature-based analyses (Ionic/University of Nottingham; CGS)|
OGC Web Services
• OpenGIS Catalog Service-Web (CSW) Implementation Specification: Defines interfaces to register metadata and to discover, browse, and query those metadata about data, services, and other geospatial resources they describe.
• OpenGIS Web Map Service (WMS) Implementation Specification: Provides operations in support of the creation and display of registered and superimposed map-like views of information that come simultaneously from multiple sources.
• OpenGIS Web Feature Service (WFS) Implementation Specification: Enables a client to retrieve and update geospatial data encoded in Geographic Markup Language (GML) from multiple Web Feature Services.
• OpenGIS Web Coverage Service (WCS) Implementation Specification: Allows access to geospatial “coverages” that represent values or properties over a geographic extent.
• OpenGIS Web Map Context (WMC) Implementation Specification: Specifies how links to WMS servers can be described in a portable, platform-independent format for storage or transmission.