An Analysis of the Distribution Characteristics of Spatial Data in a Marine GIS/Electronic Chart

Abstract An electronic chart display is being developed at Liverpool Polytechnic (UK). It is designed to automate the basic operations of navigation and simplify the presentation of information. The system makes innovative use of video as the cartographic display medium, using a frame by frame presentation of standard paper charts. The work described in this paper is discussed in relation to this chart, although brief reference is made to the emerging standards for electronic chart data exchange in digital form. Analysis of the conventional chart information model shows how various information types are related to chart usage. A model of the navigational task is proposed which relates to the different stages of voyage execution and this is further related to the implicit chart data structure. In conclusion, it is argued that ECDIS system design must account for differences in navigational circumstances and expert system technology is therefore offered as the next step in the integration of Navigation into an overall ship-control system.