General feature model Introduction to information viewpoint

© ISO 2001 All rights reserved 14 icons. Elements of semiotics form the approach of this information viewpoint on geographic imagery. Semiotics comprises the syntactics, semantics and pragmatics of signs. Figure 5 presents the semiotic-derived structure for the information viewpoint 2 . Decisions Knowledge Information Data Data with meaning assigned Integrated model of information Pragmatic application of knowledge Representation subject to interpretation Compression of redundancies Representation is described Goals of multipl e stakeholders Figure 5 – Semiotic derivation of the information viewpoint Data Figure 5, bottom layer is a reinterpretable representation of information in a formalised manner suitable for communication, interpretation, or processing [ISOIEC 2382-1]. For imagery, data is the result of a measurement by a sensor at a location. Applying conventions or agreed-upon codes is the transition from data to information. Structuring the sensor data in a standard syntax allows for transmission of the data to entities in the open distributed processing system. Information then is meaning currently assigned to data by means of the conventions applied to these data Editors note: ISO 19118 uses this definition of Information: knowledge concerning objects, such as facts, events, things, processes, or ideas, including concepts, that within a certain context has a particular meaning [ISOIEC 2382- 1]. ISO 19118 defines information as a type of knowledge whereas this Technical Specification explicitly separates information and knowledge. As information is gathered, regularities that are observed, are generalized and models are developed forming the transition to knowledge. Knowledge is an organized, integrated collection of facts and generalizations. Imagery can be interpreted based on a model of feature types that correspond to a universe of discourse. The resulting feature-based description of a scene is described in the General feature model clause. The knowledge base is used in the formation of pragmatic decisions that addresses the goals of multiple stakeholders. Key to effective decisions is identifying the context in which the decision applies. The context determines what information is relevant to the decision.

8.1.2 General feature model

Geographic imagery is a type of geographic information. The ISO 19100-series of International Standards define a conceptual modeling approach for geographic information. ISO 19101, Geographic Information – Reference Model, defines Conceptual Modeling and the Domain Reference Model that this Technical Specification extends for 2 Adapted from “A Theory of Computer Semiotics”, Peter Andersen, Cambridge Press, 1997 © ISO 2001 All rights reserved 15 geographic imagery. ISO 19109 defines the General Feature Model that is used throughout the ISO 19100-series. The Conceptual Modeling approach that is the basis for the General Feature Model is extended to geographic Imagery in Figure 6. Figure 6 - Feature modeling extended to imagery The left side of Figure 6, derived from ISO 19109, shows the process of structuring data from the universe of discourse to the geographic dataset. The definitions of the feature types and their properties, as perceived in context of an application field, are derived from the universe of discourse. A feature catalogue documents the feature types. An application schema defines the logical structure of data and may define operations that can be performed on or with the data. The right side of Figure 6 shows the process of sensing data in the environment that can be processed to provide measurements of physical quantities or to be interpreted as a set of discrete features. The physical quantities and their properties, as perceived in context of an application field, are derived from the universe of discourse. An attribute catalog documents the physical quantities as attribute types. Derived images are specializations of geographic images. An interpreted scene is not an image, but rather a discrete coverage or feature collection. Elements on the right side of Figure 6 are defined in this Information Viewpoint. Sensors and the resulting data are described in the Data clause. Image, Derived image, and the physical quantities in an attribute catalogue are described in the Information clause. Interpreted image is described in the Knowledge clause. 8.1.3 Topics relevant across data, information, and knowledge 8.1.3.1 Resolution