Status and problems of geographical information systems. The necessity of a geoinformation theory

Molenaar, M., 1991. Status and problems of geographical information systems. The necessity of a geoinformation theory. ISPRSJ. Photogramm. Remote Sensing, 46: 85-103. The fact that the field of GIS is very heterogeneous and fragmentary makes it difficult to give a status report on its development. Therefore, it is desirable to structure this field by means of a geo-information theory. The formulation of such a theory should start with the formulation of some basic concepts for geo-information and for information systems. The major pan of this article has been dedicated to these problems. It treats some important structural aspects of geo-information, such as the relationships between terrain features, their thematic attributes and their geometry. A general structure for feature classification systems has been given and different solutions for linking thematic data to geometric data. Furthermore, a discussion of the general characteristics of information systems leads to the identification of three components: the information base, the information processor and the grammar. With these basic concepts an outline is sketched of an information theory for geodata. In this sketch, problems are identified which have to be solved in the near future, such as the definition of the context of geoinformation, the definition of context transformations, the evaluation and handling of data inaccuracy and the definition of curricula for courses to train new generations of GIS professionals