Showing papers in "Cartographic Journal in 1987"

Fractal and Automated Line Generalization

Abstract: The preservation of fractal dimension is proposed as a guiding standard for the automated generalization of statistically self-similar geographical lines. Testings on two different types of such lines show that none of the current generalization algorithms most frequently cited in the literature preserves fractal dimension and statistical self-similarity in a consistent fashion. The walking algorithm used to measure fractal dimension is suggested as an alternative method for generalization. The method not only preserves fractal dimension, it also produces generalized lines whose average angularity and overall displacement are very much in line with the best results provided by other generalization algorithms.

The Mental Image in Cartographic Communication

Abstract: There has been considerable interest within cartography in the cognitive processes associated with cartographic communication. Mental imagery is thought to be an important part of cognition. It has been determined that such internal images have structural and functional properties similar to maps and may be used in answering questions based on information derived from maps. The long term function of maps in the process of cartographic communication is modelled in the form of a human geographic information system – analogous to similar computer systems.

The Evolution, Application and Implications of Strip Format Travel Maps

Abstract: Strip format maps have been used as an aid in travel throughout recorded history. The evolution of this map format from Roman times to the present is examined with emphasis on the interaction of map form and function. Particular attention is given to the range in abstractness of strip maps when used with different travel modes or applied to different kinds of travel and the relationship of strip map popularity to restrictions on travel at various points in time. The use of strip maps as spatial process descriptions of the environment is also considered in relation to a variety of travel contexts.

The South Carolina Coastline on Historical Maps: A Cartometric Analysis

Abstract: Historical maps of the South Carolina coastline were examined to determine their accuracy. Length and direction of error vectors were analyzed for statistically significant differences between individual maps and among regions within maps. Accuracy generally improved over time, but one map was found to be less accurate than expected, given its date. The direction of the error vectors tended to be aligned more with longitude than latitude. Segments of the coast with larger populations were generally more accurate than less populated areas. The northern portion of the coastline had significantly more error associated with it than other parts of the coast.

Unit-Vector Density Mapping

Abstract: An automated mapping technique, termed unit-vector density mapping, is introduced as a new method of displaying continuous surface vector quantities. With this graphic procedure, the density of short standard-length line segments (unit-vectors) with, or without, arrowheads represents geographical magnitudes and unit-vector orientation shows direction or movement. This paper describes the plotting algorithms for producing unit-vector density maps and demonstrates the versatility of this technique in a number of geoscientific applications.

Statistical determination of class intervals for maps

Abstract: There are several practical rules for determining categories (class intervals) for maps representing statistical data, like arithmetic, geometric or equal steps etc. In this paper, however a coherent method is proposed to provide statistically separable Classes on a map with minimum redundancy in terms of information content.The number of class intervals can be directly computed by means of appropriate statistical methods if the widths of classes are determined by t-test, i.e. when their difference is significant at a high level of confidence. A class narrower than this width would represent data in different categories due only to variance, however, the selection of wider classes leads to a certain loss of information.The class intervals determined this way should be positioned on the statistical data-set so that each category contains approximately equal number of data providing maximum information content of the output map. At the final step the class intervals derived this way should be rounde...

Recent Development and Future Trends in Geo-Information Systems

Abstract: Geographic information systems which store, manipulate and display spatially-referenced datasets have been in existence for many years. These systems have traditionally been used to handle digital map data in vector form, but more recently they have been used to handle raster-based imagery of the Earth's surface. There is now a need to establish integrated geo-information systems (IGIS) based on major environmental databases with intelligent front-ends, and knowledge-based systems for data management, selection, integration and display. This paper reviews the developments in these areas and assesses the potential impact of advanced information technology in the IGIS field.

The Directorate of Overseas Surveys and Mapping in Nigeria

Abstract: The Directorate of Overseas Surveys is the giant-tasked but small-establishment central mapping organisation that eventually salvaged British colonies from their state of maplessness. Its contribution to mapping in Nigeria is discussed in this paper.

CARTRIPS – A Cartographic Route Information Presentation System

Abstract: CARTRIPS is a computer system which produces personalised maps for motorists. The system allows motorists to select routes between towns or to find out where sites of interest and other travel facilities are located. This paper describes how the system operates, and shows how simple, low-cost maps can be produced quickly according to the motorist's requirements. Results from testing of the system are also described.

CARTO-NET: a relational database approach to automated map cataloguing

Abstract: Conventional automated cataloguing systems are efficient as general purpose systems, but have limitations for map holdings. Such systems are based on MARC records which nevertheless represent a national standard for bibliographic information interchange. However, the flexibility and improvement in efficiency of relational database systems offer enormous potential for new approaches to information management, including graphics-based data retrieval and automated graphic indexing. If they are to be widely used, and their potential realised however, it must be possible for them to store data in such a way that standardised records can be generated when required.The first stages in the implementation of a full-scale system of this kind for map cataloguing of sheets and their various editions within map series are described and the problems encountered discussed. The results of user-trials with the National Library of Scotland Map Room are assessed and the place of such a system within a larger scheme ...

Continental Shapes on World Projections: The Design of a Poly-Centred Oblique Orthographic World Projection

Abstract: The map projection is considered an important variable among map design elements In some instances cartographers need to consider projections on which continental shapes are closely preserved The proposition offered here is that continental shapes are best preserved on the familiar orthographic projection A world projection is devised by developing a composite of several orthographic views, each of which best illustrates the five major continents Subjects were tested for judgments of continental centres, and these are used for orienting the oblique projections The final composite world projection is new This process demonstrates how the map projection and its selection is a dynamic part of overall map design

Scientific Roles for the New Cartography

Abstract: This invited paper was presented by David Bickmore at the Annual Symposium of the British Cartographic Society at Brighton in September 1986. It is now reproduced in The Cartographic Journal as read at that meeting, with minor amendments. Mr Bickmore is Chairman of ICA/IGU Joint Working Group on Environmental maps and atlases

The search problem in automated map design

Abstract: This paper examines the principal features of the classical mathematical search problem and considers this as a model for intelligent map design. Transformation of map design into search terms reveals where the primary difficulties lie in automating map design and elucidates deficiencies both in cartographic knowledge and in methods of spatial dataset abstraction.

Automation in Cartography – Revolution or Evolution?

Abstract: The increasing sophistication in computer hardware, software, and data base development as applied to spatial data contains elements that are both revolutionary and evolutionary in nature. Capabilities in these areas continue to grow and improve but often are limited by comprehension on the part of producers and users, by lack of prudent planning, and by insufficient funds to accomplish identified objectives. In this complex situation, an important role is developing for cartographers with different skills than their predecessors, but with some similar functions: interpreting and representing spatial data for users, maintaining the spatial integrity of data and bringing expertise to the effective development of data bases responsive to a broad array of users. This paper describes aspects of the growth and development of this new role, based on experience at the U.S. Geological Survey.

Using computers to catalogue map collections – (Part 2)

Abstract: In December 1985 the authors published an article in The Cartographic Journal (Watt and Browne, 1985) describing the use of the proprietory database package called Datatrieve for cataloguing maps. This current article outlines the development and presentation of a 'front-end' which effectively hides Datatrieve and turns the facility into a very flexible menu-driven system for map cataloguing. Attention is concentrated on how to use the catalogue rather than the methods used to establish and update the collection of maps, which would primarily be the responsibility of the Map Curator.

Digital Urban Mapping

Abstract: Mapping is gradually passing from the domain of graphics to the domain of numbers. Whereas in the traditional mapping process the aerial photography has been transformed directly into a line map, the new approach to mapping yields primarily a digital representation of the area, the plotted map becoming but one of the possible output forms. The digital approach is of paramount importance in mapping at large scales, for it can easily be combined with other sources of information, also presented in digital forms, to produce a data base for managing the area.

Some Observations on Map and early America Book Publishing in early America

Abstract: Before printing was brought from England to Colonial America in 1638 the mapping of North America was conducted chiefly by the great European powers of the time. As colonization took root the craft of printing flourished, and a fledgling publishing industry emerged in the New World. This formative period of American publishing was beset by problems both technical and ethical until the end of the nineteenth century and is noted more for its prolific outpouring of printed material than for quality.