A language design and implementation for geospatial information services chaining

The Geospatial Information that service from public organizations and authorities are significantly increasing e.g., JPL OnEarth, GeoBrain, Google, and so on. Those geospatial information services rely on various existing Web technologies such as Web Service, OGC Web Services, REST, and GeoRSS. There are several formats of geospatial data which are published via the standard protocol HTTP such as GML, KML, Shapefile, and GeoTiff. Currently, a number of researches in geosciences community focus on geospatial services integration. The geospatial services integration is jointly defined and introduced by OGC and ISO TC 2111. The services integration is defined in term of service chaining: Transparent chaining, Translucent chaining, and Opaque chaining. This paper reports a research which focuses on Translucent chaining in which public user is allowed to predefine a service chain and execute it via Workflow enactment service. A process definition language is applied to coordinate across XML-based interfaces and support services chaining among Web Service, OGC Web Service, and REST. WPS-T (Transactional Web Processing Service as Workflow enactment service) is implemented and used to introduce a scalable framework. Complex geospatial operation can be managed by sequencing a number of simple operations from service itself or other services into a single operation. A geospatial service chain can then be executed as a single service operation, and it also can be invoked by other service chain. The implemented system is demonstrated to facilitate services chaining which is independent from any services interface.