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© ISO 2001 — All rights reserved
of a service chain. Here it is assumed that the chain is syntactically correct, i.e., the input and outputs types internal to a chain match and the chain produces a result. Some factors to consider in the semantic evaluation of
a chain result are listed below:
Appropriateness of starting data: are the based datasets suited to the subsequent processing? For example, accuracy and resolution of the data, thematic values are relevant.
Affect of services on data: how do the individual services effect the data, e.g., error sources and propagation. Sequence of the services: how does the order of the chain affect the results? For example, should a spatial
operation, e.g., orthorectification, be performed before or after a thematic operation, e.g., resampling the attribute values?
The evaluations depend upon understanding the services, e.g., through review of the service metadata, but also rely upon the users understanding of the combinations of the services.
8.6 Services organizer folder SOF 8.6.1 Introduction
Services organizer folders SOFs were introduced in 7.3 as groupings of services that are used for a specific task. Clause 7 introduced SOF as a structure. The remainder of this clause provides example SOFs based on the
service taxonomy defined earlier in clause 8.
8.6.2 Image Exploitation SOF
Image exploitation services are required to support most aspects of image exploitation, including precision measurement of ground positions and of object dimensions. For example, a variety of services are needed for
extracting features from images, or digital elevations from stereoscopic images. Image exploitation services are widely implemented and used in photogrammetric systems, currently using custom interfaces.
Table 12 provides an example Image Exploitation SOF.
© ISO 2001 — All rights reserved
33 Table 12 — Image Exploitation SOF
Geographic Service Taxonomy Image Exploitation Services
Human interaction services Geographic viewer – mosaicing
ModelInformation management services Coverage access service
Feature access service Catalogue service
WorkflowTask services. Chain definition service
Workflow enactment service Processing services
Processing services – spatial Coordinate conversion service
Coordinate transformation service Image coordinate conversion service
Orthorectification service Processing services – thematic
Geoparameter calculation service Thematic classification service
Image processing service Processing services – temporal
Subsetting service Subsampling service
Processing services – metadata Statistical calculation service
Communication services Geographic format conversion service
System management services
8.6.3 Geographic data fusion SOF
Geographic data fusion is a framework of services for the synthesis of data originating from different sources. It aims at obtaining information of greater quality; the exact definition of greater quality will depend upon the
application. Geographic fusion is accomplished through organizing, relating and linking disparate sources of location-based information. Geographic fusion relates to the fusion of two or more geographic elements and the
fusion of geographic elements with other sources of structured and unstructured data from distributed sources.
Table 13 provides an example Geographic Fusion SOF.
