Copyright © 2013 Open Geospatial Consortium.
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Geometry retrieval
o Use case description: support the retrieval of the geometry for non-spatial AIXM features. For instance, an AIXM Runway feature represents a
runway entity but does not contain the actual geometry; this is stored in RunwayElement features. The use case is to be able to determine and
retrieve the geometry, given the Runway feature.
o Solution: a WPS profile has been defined and implemented that accepts an
AIXM feature and that determines and retrieves its geometry from a WFS.
6.2.6.2 Functional overview
The Luciad WPS service component had the following functionality, developed during OWS-9:
WPS 1.0 service interface with support for the requests GetCapabilities, DescribeProcess and Execute.
Implementation of a WPS profile to support ePIB map generation: o Accepted Digital NOTAM events and map configuration settings.
o Interacted with OGC Catalogue Service for the Web CSW and WFS services to discover and query the necessary feature data and styling
information. o Interacted with an FPS service to render the ePIB map.
Implementation of a WPS profile to support geometry processing: o Calculation of topological relations between two AIXM 5.1 features in
ellipsoidal space. Supported topological relations: INTERSECTS, DISJOINT, EQUALS, TOUCHES, CROSSES, OVERLAPS,
CONTAINS, WITHIN, COVERS, COVERED_BY. The calculation framework is based on the Dimensionally Extended Nine Intersection
Matrix DE-9IM, which is defined in the OGC Implementation Specification for Geographic information – Simple feature access
http:www.opengeospatial.orgstandardssfa .
o Calculation of the intersection points between two AIXM 5.1 features in ellipsoidal space.
Implementation of a WPS profile to support geometry retrieval: o Determined the geometry for non-geometry AIXM 5.1 features.
6.2.6.3 Deployment characteristics
The WPS service component is based on Java Servlet technology. To run, it requires a servlet container or application server compatible with Java Servlet 2.4 or higher. Apache
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Copyright © 2013 Open Geospatial Consortium.
Tomcat 6 has been used by Luciad during OWS-9. Other than being capable of running a Java Virtual Machine 1.6 or higher and an appropriate servlet container application
servlet, no requirements are posed on the underlying hardware or operating system.
6.2.6.4 Challenges
One particular challenge identified when working on the ePIB WPS process was to get optimal performance. Due to several additional service interactions needed in this WPS
process discovery of styles and WFS URLs via a CSW, retrieval of feature data from a WFS, generation of the map via an FPS, it was a continuing challenge to achieve good
performance in calculating and rendering the ePIB map. Caching of fairly static data e.g. baseline AIXM data or styling helped, but other possibilities exist to improve the
usability for the user e.g. asynchronous generation of the map WPS allows this or a closer integration of services to reduce data bandwidth consumption e.g. integration of a
WPS and FPS.
6.2.6.5 Accomplishments
