workflow requirements, resulting in the creation of valued-added enterprise systems that demonstrate the power of interoperability and service-oriented architectures.
Earlier OWS activities started investigating geo-processing workflows, in particular the OWS-2 Common Architecture work used BPEL and WSDL to implement, test and
demonstrate OGC Web Services for Image Handling and Decision Support; there, initiative participants were able to chain several services using the Oracle BPEL product.
It was recognized in the subsequent initiative OWS-3 that workflows were not fully engaged. Therefore, there was a desire to focus on workflows in OWS-4, and in
particular coordinate with specific thematic topics. Further, it was recognized that modifications to existing specifications as well as creation of new specifications might be
needed to support robust and extensible service chaining. For example, many OGC services logically fit at the end of a service chain where operations such as getMap, and
getFeature return the results of a geospatial process. Support for transactions, portrayal and additional processing services are needed to create more comprehensive and robust
process chains. In OWS-4, transactional capability was added to the WCS and explored further with the WFS. Support for temporal data was investigated in both the WCS and
WFS. Finally new processing services were built by wrapping an existing image handling toolkit behind a Web Processing Service WPS.
As part of the workflow activities it was also necessary to develop GML application schemas for the NGA data products to be used in the OWS.
5.5.1 GML application schemas
Ease of Moving Data. To support the need for greater timeliness, readiness and accessibility of data for analysts and customers, as well as to support collaboration, the
NSG community will require a robust net-centric environment that capitalizes on the capabilities afforded by evolving e-business technologies. Future technologies, greater
network speed and flexibility, and improved network security will enhance analytic information generation and secure data sharing across security domains. Community-
funded networks will link, and web services will act upon, GEOINT data that is organized for community-wide access and sharing, using community-vetted data
models and standards.
Applicable OGC Specifications and developments • GML 3.2.1 OGC 07-036
• GML 3.2 OGC 05-108r1 • GML 3.1 OGC 03-105
• AIXM Mapping IPR OGC 07-029 • Application Schema Tailoring and Maintenance Discussion Paper OGC 05-117
• Image Geopositioning Metadata GML Application Schema OGC 06-055r2
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Discussion of applying OGC specifications to meet NSG objectives
Application schemas based on OGC’s Geography Markup Language Version 3.2 GML3 were developed as part of OWS-4 to test the feasibility of GML3 to encode
NGA data and serve as a standards-based vector data transfer format. This work built upon earlier OWS efforts that utilized GML2 application schemas and data instances.
This section describes the development of GML3 and UML application schemas to support the NSG Feature Catalog NSG FC, NGA’s Mission Specific Data MSD as
well as NGA’s Aeronautical data content to support Vertical Obstructions VOs, Stereo Airfield Collection SAC and Digital Aeronautical Flight Information File DAFIF
data.
Note: The term NSG Feature Catalog NSG FC was originally used to denote the source of the information that fed into the application schema development process. The NSG
FC contains much more information than is described in ISO 19110, and therefore the use of the term was not appropriate in the context of application schema development
process. The term GEOINT Structure Implementation Profile GSIP will be used when referring to the inputs of the schema development process. The term NSG FC will only
be use when actual Feature Catalog is referenced.
Mapping an ISO 19100 UML Application Schema to a GML Application Schema Various OWS activities have lead into the development and refinement of the XMI-based
UML-to-GML-Application-Schema UGAS conversion tool ShapeChange.” see:
http:www.ogcnetwork.netugas . The tool has been updated several times through
experience in OWS-2 and OWS-3 initiative. Most recently in OWS-4 the tool was upgraded to support GML 3.2 application schemas. The process is described graphically
in the figure 11 below.
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