Copyright © 2011 Open Geospatial Consortium.
13 supports the ability to publish and search collections of descriptive information metadata for data,
services, and related information objects. This metadata is encoded using the OGC Styled Layer Descriptor SLD standard to enable its use by Feature Portrayal Service FPS components. The
Style Registry is used in the SAA Pilot Study to catalog, manage, discover and access symbols, and styles as a repository of map styling used by the FPS to support SAA geospatial data display by the
OGC Application Client components.
5.5 Feature Portrayal Service
The Feature Portrayal Service FPS is a type of OGC Component Web Map Service WMS that can symbolize feature data obtained from one or more remote WFS components. The term FPS is
defined in the Styled Layer Descriptor Profile of WMS SLD-WMS, OGC Specification 05-78r4, and describes a Web Map Service capable of receiving an SLD Document. The specification actually
describes two types of SLD-WMS, the Integrated WMS that is connected to a database, and the Component WMS or FPS which is capable of styling data from a compliant WFS. The latter is
more flexible and is the type used in this trial.
An FPS allows for flexible binding of arbitrary GML data sources and applicable styling rules for inclusion in a client display. Typically, an FPS has the following characteristics:
It has no pre-defined ‘named’ styles or layers i.e. it acts as a portrayal engine rather than a data source.
It only supports the WMS OGC standard interface. It can symbolize feature data from any compliant WFS component or GML data.
It supports user-defined styles, symbols, and map layers.
Styles, encoded using OGC Symbology Encoding SE, describe styling attributes that can be applied to particular features in the portrayal process. Symbols are generic graphical entities
referenced in styles and used by the FPS in the styling process
One of the objectives of the FAA SAA Dissemination Pilot is to lower the barrier for client use of SAA information by leveraging the OGC separation of Portrayal Rules, Symbol Sets, and Portrayal
specifications from underlying geospatial data. This allows users to define and apply different stylessymbols to the same feature data depending on the chosen styling rules, which may have
different styles or conventions based on the type of Client or User Community. The separation is achieved by using the FPS as a portrayal engine for the SAA geospatial data to allow the generation
of customizable maps with localized standards for symbology styles and symbols and portrayal rules.
5.6 Application Client
OGC-compatible application clients provide a user interface for the retrieval and display of geospatial features and their properties that are obtained from WFS and ES components. Vendors of
several commercial OGC client applications participated in the Pilot Study to show how SAA information could be presented to the aircraft pilot or air traffic controller.
Commercial products from Envitia, Luciad, and Lufthansa Systems participated in the Pilot Study technical interoperability exercises to demonstrate how OGC standards facilitate the dissemination of
information among software products developed by different vendors. Typically two general forms of client exist; the thick or rich client, typically developed using a high level language to implement
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significant client-side functionality such as the Luciad and Lufthansa Systems products, and light or browser-based clients such as Envitia, developed using JavaScript and HTML to exploit
functionality in the service platform.
6 SAA Dissemination Scenarios
An operational Commercial Flight scenario was developed to demonstrate OGC component capabilities to disseminate SAA information and events. The component capabilities were described
in a number of Use Cases. Additional scenario topics, queries and filters that could also be used to demonstrate features of the SAA Pilot architecture are provided in Annex E.
6.1 WFS Use Cases
