Cartographic Algorithms: Problems of Implementation and Evaluation and the Impact of Digitising Errors

Cartographic generalisation remains one of the outstanding challenges in digital cartography and Geographical Information Systems (GIS). It is generally assumed that computerisation will lead to the removal of spurious variability introduced by the subjective decisions of individual cartographers. This paper demonstrates through an in‐depth study of a line simplification algorithm that computerisation introduces its own sources of variability. The algorithm, referred to as the Douglas‐Peucker algorithm in cartographic literature, has been widely used in image processing, pattern recognition and GIS for some 20 years. An analysis of this algorithm and study of some implementations in wide use identify the presence of variability resulting from the subjective decisions of software implementors. Spurious variability in software complicates the processes of evaluation and comparison of alternative algorithms for cartographic tasks. No doubt, variability in implementation could be removed by rigorous study and specification of algorithms. Such future work must address the presence of digitising error in cartographic data. Our analysis suggests that it would be difficult to adapt the Douglas‐Peucker algorithm to cope with digitising error without altering the method. Copyright © 1991, Wiley Blackwell. All rights reserve

Pretty maps: evaluating GIS adoption of cartographic design standards and best practices in professional publications

The nature of GIS maps, as tools designed for visual communication, puts them in the realm of art that is in many ways unique among scientific tools. As a visual form of communication, maps are responsive to methods of visual design, affecting the map’s appeal and function. Through cartography, a well established body of standards and best-practices exists to help GIS users avoid common design errors and create effective and meaningful maps that support their work. This research examines the adoption rate of those standards amongst professionals using GIS software for creating maps for journal publications. A selection of 80 GIS-produced maps from the AAG’s Professional Geographer were examined and compared to a uniform set of cartographic standards to look for trends in the adoption rates of map design standards amongst GIS map makers. Maps were rated by the author on their use of cartographic standards based on map content and purpose as opposed to their aesthetic quality. The data show trends in GIS cartographic design use that closely follow the inclusion of default values in common GIS software. The implication is that GIS professionals making maps are typically not applying cartographic standards on their own, but mostly following the standards set up in their software of choice. This suggests that there is still significant work to be done in teaching the value of cartographic principles to GIS students and practitioners

Resolution Study

Resolution effects on cartographic data using conventional stereoplotters with photographs taken at orbital height

Microeconomic and Geo-physical Data Integration for Agri-environmental Analysis, Georeferencing FADN Data: A Case Study in Italy

The authors, inside a TAPAS action, have developed a methodology - based on the integration between FADN data with statistical, administrative and cartographic information - to improve the production of statistical data related to agricultural policies impact on land and environment. This methodology allows - using Geographic Information System (GIS) technology - to produce and organise data at geographical level. Data spatially referenced respond to the specific needs of agri-environmental analysis and problems, mostly related to specific areas (environmental vulnerability areas), inside defined boundaries (e.g. river basin). The GIS is implemented with several cartographic layers (Topographic and cadastral maps, land use, soils, water sources, climate, Digital Terrain Model etc.) and is related to the regional FADN database.agricultural statistics, agri-environment, FADN, GIS, TAPAS, DPSIR, Environmental Economics and Policy, C81, O13, Q21,

Applications of remote sensor data to cartographic programs

Spaceborne photography applied to cartograph

Cartographic evaluation of ERTS orbit and attitude data

There are no author-identified significant results in this report

From the cartographic gaze to contestatory cartographies

Rene Descartes declared in the 16th Century that the world was now dominated by the visual, a notion that would be seen as defining the Enlightenment (Descartes, cited in Potts, 2015). As the increased dominance of seeing and the desire to visualise the world cohered with the production of increasingly accurate tools of measurement and the advent of the printing press, cartography emerged as a discipline, often used as tool of oppression and dominance. Cartographic visualizations, afforded the creator, and user, a Gods eye view of the world. Following others (See Casas-Cortés et. al., 2013; Koch, 1998), this chapter refers to this way of seeing the world from above as the Cartographic Gaze. First, the chapter briefly examines the historical emergence of the Cartographic Gaze before turning to a discussion about how the proliferation of geographic imaging technologies and digital tools simultaneously further embedded this gaze into mapping practice, while also diffusing such practices of mapping to broader populations. Discussing the rise of participatory mapping and counter mapping under the rubric of contestatory cartographies, the chapter presents some of the challenges that face those attempting to create alternative maps of their worlds, and the ways in which they become entrapped by the pervasiveness of the Cartographic Gaze. We use the term participatory mapping to refer to methodologies for map-making based around the participation of those who the map will represent. And we employ the term counter mapping to reference those mapping practices that explicitly seek to expose and challenge power relations. In specific, we look at how the colonizing origins of the Cartographic Gaze limit what it is possible to do with these alternative mapping practices

The (unknown) role of map librarian and the challenge of satisfying the cartographic user needs

The (unknown) role of map librarian and the challenge of satisfying the cartographic user needs The profession of librarianship is developed and is being recognized in Sri Lanka. But we have neither heard of a map library nor a map librarian in our local environment. In Europe and USA map libraries are well known and map librarians are recognized Librarians who deal with maps come under the special library group and have to manage the map collection in a special manner. It needs specialized knowledge in managing map collection. Reading of maps needs technical equipments and storage and preservation too is different from books. Hence the librarian who deals with maps should undergo training to familiarize himself/herself with the technical methods of storage, search co ordination and manage archives and enhance access of cartographic materials. After world War 11 traditional map depositories are converted into cartographic centres and new technology is heavily used in map production, storage and usage. This paper highlights the role to be played by map librarians in a modern library using new technologies. Map users are very much advanced in using different type of technologies in reading, creating, copying etc.maps. This technological advancement has not caused much change in map collection in the developing countries. Even in the 21st century we see the traditional collection of maps in Sri Lanka. . While studying the situation (advance collection and advance users) in other countries, a sample study was carried out with reference to the local environment by selecting academic and special library groups. This paper elucidates the role played by a librarian who handle maps, who is not recognized as a map librarian It also discuses the attitudes of the cartographic users towards map libraries in our country the institutions where map collections are available, the barriers experienced by the users in accessing the collections, important issues neglected by the higher authorities and lack of a national body to authorize map production in the country. The role that could be played by the national body or a regulatory body such as management of collection and databases, setting of standards, copyright law and implementing a national policy in map production and the problems faced in producing maps are discussed. The study reveals that the gap between the traditional map libraries (collection) and the users of cartographic material is widening. The author suggests that the librarians could overcome this problem by undergoing professional training. This will change the attitude of the users towards the map librarians and map libraries. This will give recognition to the professionals who work as map librarians

Users characteristic influence on the efficiency of typographic design

This paper investigates the efficiency of typographic design using Bertin’s variables, both individually and combined. A user study was con-ducted in which two types of map users had to perform a search task. The first group consists out of participants who have been trained in cartog-raphy and who use maps on a daily basis. The second group of users are novices who have not got any previous education in cartography. Users’ efficiency was calculated by measuring the consumed time to find the target label. The obtained data was analyzed statistically to compare the efficiency of users’ performance regarding the applicability of visual variables on la-bels. Using ANOVA showed some significant differences between users’ group and within users’ groups (P<0.05)