Future Work Topic 16 - Image Coordinate Transformation Services

6. Future Work

Further refinement of the object models in this document appears needed. In particular, further work is needed on the abstract model for the Imaging Time Determination Service. Specification and implementation of the imaging time determination service probably depends on specification of temporal reference systems. Complete specification of temporal reference systems has been put off for future work by the OGC. Therefore, complete specification and implementation of this imaging time determination service will be delayed. As stated in Section 2.10.3, the OGC probably should cooperate with the International Society of Photogrammetry and Remote Sensing ISPRS in defining standard image geometry models and submodels. The next ISPRS meeting is scheduled July 19-25, 2000, in Amsterdam, The Netherlands. The IES SIG and probably the CT WG should participate in related ISPRS sessions. Further refinement of the object models in this document is also needed to represent and access the metadata needed to describe specific data objects and services. Work on service metadata has started in the Metadata SIG and the Architecture SIG. There are several possible approaches to abstract modeling of metadata using UML, including: 1. Metadata Operations – One approach would be to provide metadata retrieval operations in each class that needs metadata. This is the approach previously suggested in Section 4.1 of this Topic Volume. 2. Metadata Classes – Another approach would be to provide metadata classes that are associated with each data and service class which needs metadata. The CT ad hoc working group has tentatively decided to pursue this approach. 3. Metadata Attributes – Another approach would be to provide metadata attributes in each data and service class that needs metadata. These three approaches are not mutually exclusive. Different approaches could be used in different places. Alternately, two approaches could be used together. For example, metadata retrieval operations could be used to create actual metadata objects that are associated with each data and service object that needs metadata. The Open GIS Abstract Specification Page 50 Volume 16: Image Coordinate Transformation Services 00-116.doc

7. Appendix A. Acronyms and Glossary