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Copyright © 2011 Open Geospatial Consortium.
The WFS enables users to perform a wide range of queries from simple queries: Get me all features within a bounding box
Get me the Airspace with the identifier: eafcbdff-e8cc-4afd-beb3-3c08883b7b1d
to more complex queries: Get all active Airspaces within 200 nautical miles of a route
Get the names of all military Units operated by US Navy
5.2 Event Service
As part of the OGC Web Services OWS initiative, the OGC has developed a service specification for event notifications based on the OASIS Web Services Notification standard. An Event Service
allows users to automatically receive notifications about feature-related events, which represent updates to feature property values state changes. This is analogous to the asynchronous SAA
Service publishsubscribe pubsub topics implemented using the Java Messaging Service JMS standard, but without vendor-specific JMS binding issues. In addition, the Event Service subscription
can include filter criteria for pre-defined event topics as well as filters that operate on the spatial, temporal andor thematic properties of events, much like the WFS filters.
Details on the Event Service implementations used in the Pilot Study can be found in section 7.1. The encoding of the events used in the Pilot Study is also described in section 7.1. The Event Service
design also includes a standard “heartbeat” channel to allow subscribers to confirm the continuing availability and connectivity to the Event Service see section 8.8.
5.3 Event Service Adapter
The Event Service Adapters, provided by Snowflake Software and IfGI, act as the data source for the OGC Event Service. The Event Service adapters integrate information from the SUA reservation
schedule data feed with data derived from the BASELINE data from the SAA WFS. The Event messages were augmented with additional metadata to enable:
Spatial filtering within subscriptions: by populating the bounding box geometry of airspace reservation change events generated by the Event Service Adapter
Identification of Event publisher: by adding ISO encoded metadata in the Airspace timeslice
SAA airspace reservation changes schedule events are obtained from periodic polling and analysis of schedule status listings provided by an FAA website. An Event Service Adapter is used to infer
the occurrence of an SAA event by comparing the corresponding “schedule ID” values across two sequential listings and identifying when each airspace reservation request has been submitted,
approved or disapproved, and cancelled or completed. The Schedule Event Service Adapter will check for SAA reservation updates on the FAA website, integrate the information with the airspace
definitions from the subscriber file provided via WFS, and forward the event messages to the Event Service for dissemination to the application clients. Details on the available implementations can be
found in section 7.2.1 provided by IfGI, and section 7.2.2 provided by Snowflake Software.
5.4 Style Registry
The Style Registry is an implementation of the OGC Catalog Service Implementation Specification 2.0.2, based on the OWS-7 design of an aviation portrayal registry model. The OGC Catalog Service
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
