bluuebunny/crossref_metadata_2025 huggingface dataset:
Dtermination En Mode Maill Du Champ D'intervisibilit Dans Un Modle Numrique De Terrain
Authors: Donnay Jean-Paul
Published: April 2007

Cet article propose un algorithme original pour la rsolution approche, mais rapide, du champ d'intervisibilit dans le contexte d'une modle numrique de terrain maill (MNT raster). L'algorithme est bas sur la recherche des intersections potentielles de la surface orographique avec tous les rayons mens depuis le point de vue vers les pixels situs sur les bords du rectangle capable du MNT. Le chemin des rayons est dtermin par l'algorithme classique de Bresenham et, au fur et   mesure, la visibilit des pixels situs sur leur parcours est mise   jour. Une brve application de l'algorithme, implante sur microordinateur, illustre l'article.
Mathematical Morphology Applied to Raster Generalization of Urban City Block Maps
Authors: Cámara Manuel , López Francisco
Published: April 2007

This study demonstrates the application of a morphological generalization system to a set of areal features with complex relations (city blocks). It evaluates its effectiveness using a set of indexes derived from a comparison of the automated results with manual generalizations. The results show that this system can be used as a first approach for an automatic or semiautomatic mechanism and that it is also a more objective method for solving scale change problems in urban maps.
THE HISTORY OF HYDROGRAPHIC SURVEYING IN BRITISH COLUMBIA
Authors: SANDILANDS R W
Published: April 2007

This paper traces the progress of hydrographic charting on the west coast of Canada from the 18th Century to the present time. The work of the Spanish, British, and later, Canadian hydrographers is detailed by describing the areas surveyed and the methods used in surveying. The author points out the close connection between this work and the settling and development of the coast of British Columbia.
VISUALS IN TELEVISION/TECHNICAL CONSIDERATIONS
Authors: HOMER DAVID A.
Published: April 2007

Every television presentation uses some kind of graphic material or "visuals" among which the map can be of considerable significance. In order that visuals achieve a maximum of effectiveness, certain technical considerations imposed by the nature of television technology, and the many possibilities of the medium need to be appreciated. While this article does not deal exclusively with the map as a visual, it is intended to give the cartographer insights into some of the problems and potentialities of television and to stimulate thought about the need for creativity in preparing maps as visuals for television.
The Role Of The User In The Map Communication Process: Obtaining Information From Displays With Discrete Elements
Authors: Williams L.G.
Published: April 2007

When searching for an item of information in a crowded visual field, one must first see it extrafoveally (i.e., outside of central vision). The efficiency in acquiring a target item depends on how well it can be discriminated extrafoveally from other objects on the basis of its known characteristics. We define the discriminability of a specified target from a second class of objects by a searcher's ability to selectively fixate objects of the target class. By recording visual fixations during search, we have measured discriminability of objects along several stimulus dimensions (viz., color, size, shape, lightness). Lorsqu'on recherche un élément d'information dans un champ visuel très encombre, on doit d'abord le percevoir à l'extérieur du foyer visuel central. La facilite de discernement d'un élément-cible dépend de l'aptitude a le distinguer des autres objets à l'extérieur du foyer visuel central a l'aide de ses caractéristiques connues. La discernabilité d'un élément-cible parmi d'autres objets d'une catégorie différente est fonction de l'aptitude du chercheur a percevoir sélectivement les éléments de la catégorie visée. En relevant les foyers de concentration visuelle durant la recherche, il a été possible de mesurer la discernabilité des objets en fonction de divers stimulants visuels (couleur, dimension, forme, contraste).
EDUCATION IN LAND INFORMATION MANAGEMENT
Authors: Dale Peter
Published: April 2007

The origins and significance of land information systems (LIS) and their role in developed and developing countries are identical. The paper develops a relationship between measurement science and quality control in the acquisition of data Land, with its many associated attributes, is seen as 'extending from the centre of the earth to the infinite in the sky'. The role of hardware and software and the extent to which it is necessary to know and understand the inner workings of the "black box" are discussed. The intellectual challenge posed by the integration of land, information and management is explored and the difficulties of reconciling breadth with depth highlighted.
MAP READING TASKS APPROPRIATE IN EXPERIMENTAL STUDIES IN CARTOGRAPHIC COMMUNICATION
Authors: BOARD CHRISTOPHER
Published: April 2007

The rigorous evaluation of maps must be based upon map reading tasks that are appropriate to the map reading objective. Only by showing the links between purpose, map design and map reading will it ultimately be possible to establish standards of map design that are more than conventional and aesthetic. Distinctive and appropriate map reading tasks are required for navigation, measurement, visualization and the study of geographic covariation. Valid experimental conclusions can be obtained by asking the right questions and by testing hypotheses which are based upon the way in which map readers normally use maps.
The Effect Of Data Precision On The Calculation Of Slope And Aspect Using Gridded Dems
Authors: CARTER JAMES R
Published: April 2007

Plots of the frequency of occurrences of aspect angles calculated from gridded DEMs showed inordinately large spikes at the cardinal directions. Because such frequencies are not natural, the techniques of calculating slope and aspect were examined. Ultimately, the cause of the spikes was found to be the fact that the elevation values are reported only to the nearest meter. Calculations of slope and aspect angles using rounded elevation data from simulated surfaces of known slope and aspect demonstrate the nature of the problem. These simulations show that the problem of defining aspects is greatest on the most gentle slopes, as well as smaller grid spacings. Consideration was also given to various techniques of selecting elevations for deriving the parameters in the slope and aspect equations. At lower slopes, calculated aspects may be off by tens of degrees. Because there is no way to make the data more precise, researchers should exercise caution in making interpretations of aspect angles. Calculations of slope angles are affected by data precision but not as dramatically as in the calculations of aspect angles. Les tracés de la fréquence des occurences des angles d'aspect, calculés à partir de quadrillages de MNE, ont montré des pics excessivement grands vers les points cardinaux. Parce que de telles fréquences ne sont pas naturelles, on a examiné les techniques de calcul de pente et d'aspect. Finalement, on a trouvé que la présence des pics était due au fait que les valeurs d'élévation sont reportées au mètre près. Les calculs des angles de pente et d'aspect à partir de données d'élévation arrondies, provenant de surfaces de simulation de pente et d'aspect connus, démontrent bien la nature du problème. Ces simulations montrent que plus les pentes s'adoucissent et plus l'intervalle du quadrillage se rapetisse, plus le problème de définir les aspects s'accroît. On a aussi considéré diverses techniques pour choisir les élévations afin de dériver les paramètres dans les équations de pente et d'aspect. Dans les pentes les plus douces, les aspects calculés peuvent être erronés de dizaines de degrés. Parce qu'il n'est pas possible de rendre les données plus précises, les chercheurs devraient démontrer de la prudence en interprétant les angles d'aspect. Les calculs d'angles de pente sont affectés par la précision des données, mais pas aussi dramatiquement que dans les calculs d'angles d'aspect.
The Map as Intent: Variations on the Theme of John Snow
Authors: Koch Tom
Published: April 2007

"Critical geographers" concerned with cartography insist maps are first and foremost social artefacts that must be "read" as authorial documents rather than perceived as data statements. Their argument is typically dismissed as trivial because the relation between intent and output has rarely been demonstrated in a critical way. This article seeks to demonstrate the degree to which authorial intent defines map content and appearance through an analysis of a single set of maps. All are based on the original data collected in 1854 by Dr John Snow as part of his study of the cholera outbreak in London's Soho district. Snow's original map is included as baseline for a study that includes versions of the Snow map by a range of authors, including Cliff and Haggett; the US Centers for Disease Control; Gilbert; Tufte; and Monmonier. The resulting appropriations bear progressively less resemblance to the original work, despite the use of the same data set and its clear availability. The result is a cautionary tale of the distance between maps and the data they represent. The article also insists upon the close relation between authorial intent and mapped result irrespective of the data available. Finally, the article concludes that because mapping is not value-free, dangers occur when professional cartographers and geographers attempt to map data from fields in which they are ignorant.
Unclassed Choropleth Maps Revisited/Some Guidelines For The Construction Of Unclassed And Classed Choropleth Maps
Authors: Kennedy Susan
Published: April 2007

The debate over the value of unclassed versus classed choropleth maps is revisited and updated in light of new research which confirms the communicative effectiveness of unclassed maps. A resolution-independent algorithm for continuous tone unclassed maps is introduced and some guidelines are suggested for the appropriate use of both classsed and unclassed maps.
GIS Capacity Building in the Pacific Island Countries: Facing the Realities of Technology, Resources, Geography and Cultural Difference
Authors: Britton James
Published: April 2007

Historically, development projects in GIS and related disciplines implemented by Western agencies in developing countries have reflected the importance placed on advances in technology and method by Western GIS literature and industry. Such projects, which often focus on human development activity, attempt to replicate operating environments in the West within organizations in the developing world. Such an approach reflects a modernization model for development and is, it is suggested, potentially inappropriate for the needs of developing countries. Based on preliminary work conducted as part of an overall study of GIS development in the Pacific Island countries, this article examines some of the problems surrounding GIS education and training efforts in the region.

While recognizing the importance of GIS to developing countries, the article draws a comparison between approaches that reflect the interests of those supplying and those receiving such assistance. Problems cited in the implementation of effective education and training programs include an emphasis on technical issues, an unclear knowledge and skill base for GIS, short-term and disparate educational and training opportunities, and a small user community in the Pacific Island countries. Different types of educators and trainers are profiled, as well as different types of learning opportunities.

It is suggested that learning projects that focus primarily, and at all stages, on the needs of recipients and are implemented over longer time frames stand a greater chance of success and will have enduring effect. The importance of regionally based development and educational organizations that provide longer-term support to local GIS organizations is highlighted. An argument is made for including human resource development components in all GIS projects executed by external agencies as well as for the systematic support of user groups and other mechanisms that both initiate and nourish GIS awareness and understanding. The emphasis on diverse and longer-term learning opportunities is tied to a suggested "richer" approach to GIS development - an approach that addresses the wider needs of individuals working in GIS and takes into account different learning styles found outside the developed world. Lastly, it is suggested that more research is required that draws together GIS and development theory in order to more carefully assess the nature and impacts of GIS implementation in the developing world.
The Ethnography of Maps: The Cultural and Social Contexts of Cartographic Representation in Peru
Authors: ORLOVE BENJAMIN
Published: April 2007

An examination of five contemporary maps of Lake Titicaca, Peru, three drawn by government officials and two by peasants, reveals profound differences in the depiction of the natural landscape and social groups. To understand these differences, and to explain why neither government officials nor peasants are conscious of them, two techniques of map study are presented: the analysis of form and the analysis of practice, the latter consisting of an 'ethnography of viewing' and an examination of culturally specific map categories. The general implications of such incommensurabilities of mapmaking and map-viewing traditions are discussed. Un examen de cinq cartes contemporaines du Lac Titicaca, au Pérou, dont trois ont été dressées par les officiels du gouvernement et deux par des paysans, révèle des différences profondes dans la représentation du paysage naturel et des groupes sociaux. Pour comprendre ces différences et pour expliquer pourquoi ni les officiels du gouvernement ni les paysans n'en sont conscients, on présente deux techniques d'étude cartographique : l'analyse de la forme et l'analyse de la pratique, cette dernière consistant en une 'ethnographie du visionnement' et un examen de catégories cartographiques spécifiques à la culture. On discute des implications générales de telles incommensurabilités que représentent les traditions de fabrication et de visionnement de cartes.
Maintaining Orientation Within Route-Following Tasks
Authors: WALSH S. E. , MARTLAND J. R.
Published: April 2007

Contemporary evidence suggests that young children are able to use maps in route-following tasks if the map is oriented throughout the task, and that orientation within route-following tasks relies on the use of two basic strategies, i.e., one based on the compass, and one based on landmarks. An initial experiment with children aged 7 to 10 years showed that 8-to-10-year-old children have naturally-developed orienting strategies, whereas 7- to-8-year-old-children have not. In a second experiment, it was shown that children aged 7 to 8 years could learn to use the two basic orientation strategies.

The authors found, in a small qualitative study, that children aged 9 to 11 years used both strategies selectively, depending upon the environment. In familiar, known environments, the use of a compass-based strategy for orientation was high; whereas in familiar but unknown environments, and unfamiliar unknown environments, orientation strategies were used selectively: typically, the compass-based orientation strategy was used for initial orientation at the beginning of the route and at predetermined checkpoints along the route; the landmark based strategy was used for maintaining and reinforcing orientation within the route.
"Could I but Mark Out My Own Map of Life": Educated Women Embracing Cartography in the Nineteenth-Century American South
Authors: Richards Penny
Published: April 2007

In the early 1870s, instead of writing a story, drawing a picture, or composing a poem, William Henry Bailey made a hand-drawn map for his ailing mother. Despite its lack of beauty, its contents betray its unique and poignant intent: the map shows Hillsborough, NC, as it might have appeared in 1839, when Priscilla Bailey was a young wife and mother, surrounded by friends and social activities. Decades later, when Priscilla was living far from all that and recovering from a bad fall, her son created his map, with its narrative explanation of every detail, to comfort his mother by reminding her of happier days and treasured connections. Why did Bailey - a lawyer with no particular expertise in drafting, surveying, or drawing - decide to make a map to stir healing memories in his mother? The answer may lie in an evocative cartographic culture among elite Southern women of her generation. Educated to use maps, engaged daily with graphic information in their sewing and needlework patterns, and frequently separated from kin and other loved ones, these women turned to the cartographic form with familiarity and an expectation of solace. They used geographic vocabularies and metaphors to express their sense of isolation and their need for connection, even as gender norms and physical realities limited their travel and restricted them to their homes. In this article, the practice and implications of this emotional cartographic culture are explored through the examples of two women, Priscilla Bailey and Ellen Mordecai; this exploration is intended to demonstrate the value of a manuscript-based, biographical approach to the history of domestic map use.
CARTOGRAPHIC RESULTS OF THE GENERAL SURVEY OF RUSSIA 1766–1861
Authors: TSVETKOV M. A.
Published: April 2007

The late author (1875–1960), who specialized in the historical geography and mapping of forests, describes the atlases, maps, plans, and notes produced by the General Survey of thirty-five provinces of European Russia in the last half of the 18th and the first half of the 19th century. He discusses the purpose, administration, coverage, and duration of the survey and the content, value, and location of the resultant maps and notes, almost all of which have survived in unpublished form in various Soviet archives. Their value for historical geographers is illustrated by several excerpts. L'auteur, maintenant décédé (1875–1960), qui se spécialisait dans la géographie historique et la cartographie des forêts, décrit les atlas, cartes, notes et plans produits par les services cartographiques de trente-cinq provinces de la Russie d'Europe durant la deuxième moitié du XVIIIe siècle et la première moitié du XIXe siècle. Il traite des buts, de l'administration, de l'étendue et de la durée des levés ainsi que du contenu, de la valeur et de la localisation des cartes et notes qui ont été produites au cours de ces levés et qui, pour la plupart, existent encore aujourd'hui dans les archives de l'U.R.S.S. à l'état inédits. Leur valeur pour le géographe historique est illustrée au moyen de plusieurs extraits.
THE POLITICAL ECONOMY OF GIS: THE SPREADSHEET AS A LOW COST GIS
Authors: Campbell Noel
Published: April 2007

The concept of GIS can be effectively experienced without the need for expensive and specialized hardware and software. Assumptions made in the literature that GIS is an exclusive development and GIS curriculum statements that place proprietary software at the centre point of the curriculum are criticised. It is argued that the GIS specialist needs a balanced education which will help each one to be sensitive to the whole intellectual, organizational and skills context within which changes are being introduced. It is still possible for small departments to achieve this. An example of GIS applications including map output are discussed using a commonly available spreadsheet package.
AARON ARROWSMITH'S TOPOGRAPHICAL MAP OF SCOTLAND AND JOHN MACCULLOCH'S GEOLOGICAL SURVEY
Authors: BOUD R C
Published: April 2007

This paper discusses the first large-scale geological map of Scotland, published in 1836, and prepared from geological surveys that John Macculloch carried out single-handed over a period of 20 years. Macculloch's geological map was based on Aaron Arrowsmith's topographic map of Scotland in 1807 at the scale of 4 miles to the inch. The writer describes the problems experienced by Arrowsmith in compiling his topographic map and emphasizes the difficulties encountered by John Macculloch in using this map on which to base his geological data.
CULTURED SYMBOLS / THOUGHTS ON THE CULTURAL CONTEXT OF CARTOGRAPHIC SYMBOLS
Authors: WOOD DENIS
Published: April 2007

The history of cartography is so deeply embedded in ordinary map-readers by the process of development and socialization that it is simplistic to approach symbols as little more than perceptual mechanisms. Even the symbols used by three-year olds, at least with respect to hillsigns, are less perceptual than cultural products, though the embedding of the one in the other (because of the embedding of the processes of discovery, or adult development, in the processes of transmission and education) ensures that they finally represent an organic fusion of both. In mastering increasingly abstract cartographic symbols, the maturing individual masters his entire culture history, elaborated in response to both social expediency and the structure of discovery (development). In creating successful new symbols, the generative cartographer will necessarily follow a similar path.
The Interface Of Cognitive And Psychophysical Research In Cartography
Authors: Gilmartin Patricia P
Published: April 2007

The interface of psychophysical and cognitive research is not an edge but an intersection. This has important implications for cartographers who often turn to the discipline of psychology for theory and methods that can be applied to the study of maps and map-use. In the past, cartographers frequently have taken a psychophysical viewpoint in their experiments. This approach has been criticized, however, and recently, a few studies have appeared which employed a cognitive or an integrated cognitive/psychophysical viewpoint. The position is taken here that there is a need in cartographic research for all three kinds of experiments: the primarily-psychophysical, the primarily cognitive, and the integrated psychophysical/cognitive. This belief is based on two factors: 1 there are certain cartographic questions that can best be answered through a specific experimental paradigm; and 2 the interaction between cognitive and psychophysical relationships in perception creates the need for some understanding of both in order to understand either. Examples are given as to how this interface can be used constructively by cartographers in their research and how it may intrude upon and confound the results of some studies.
Geo-cybernetics: A New Avenue of Research in Geomatics?
Authors: Reyes Carmen , Fraser Taylor D.R. , Martínez Elvia , Caloca Fernando López
Published: April 2007

The term “geomatics” has existed in the literature for more than a decade, but an overall consensus on the definition of this emerging discipline has not yet been found. The knowledge domain of geomatics has developed in the “interaction space” among converging disciplines (e.g., geographic information systems, cartography, remote sensing, geodesy, and photogrammetry), but its borders are “complex and fuzzy.”

Taking cybernetics, both classic and second order, general systems theory, modelling, and complexity as basic building blocks, the research group at CentroGeo is conducting empirical and theoretical work on three main avenues of research: (1) cybercartography, (2) complex solutions in geomatics, and (3) collective mental maps. Recent research results on cybercartography have indicated the value of building a comprehensive theoretical framework that would combine the essence of these three research avenues as a body of knowledge and add to the base of knowledge on geomatics.

This article discusses the cybernetic nature of these three research avenues from a theoretical perspective and points to possible areas for further research. In so doing, the authors illustrate the benefits of taking a fresh look at the linkages between cybernetics and geomatics and identify the main elements required to develop a theoretical framework for the concept of geo-cybernetics.
The Modified Polyconic Projection
Authors: Haines G V
Published: April 2007

On many general small-scale maps of Canada two projections are used, a Lambert Conformai Conic south of 80°N, and a modified polyconic projection north of 80°N. This latter projection is derived mathematically in the present paper. A general family of polyconic projections is discussed first (including the simple or ordinary polyconic), and the rectangular polyconic is then derived as the orthotomic (or rectangular) subfamily of this general family. The longitude function and one of the scale constants defining the orthotomic subfamily are then determined to obtain a match, along a selected circular parallel, with another projection whose scale is constant along that parallel. On the Canadian maps, the selected parallel is 80°N and the other projection is the Lambert Conformal Conic. A second scale constant is arbitrary and gives the scale along the central meridian; on the Canadian maps it is taken equal to the Lambert scale at 80°. A figure of the Canadian modified polyconic map is given, north of 80°N, showing the scale distortions along parallels and meridians.
Logarithmic Urban Thematic Mapping In Mis Environment
Authors: Boutoura Chryssoula
Published: April 2007

An application of logarithmic azimuthal projection is presented for use in Municipal Information System (MIS) environment in order to treat the problem of dense concentration of urban thematic symbolism over a limited portion of the city plan keeping at the same time the general overview of the whole urban layout. The test was applied to the Greek city of Volos in Thessaly, performing a projection to projection type of analysis and the relevant study of deformations. The use of such projections is of particular importance, as experience confirmed, for hard-copy urban map products in a variety of applications interesting town planners, traffic engineers, municipal administrators, public security officers, archaeologists, professional associations and other specialists dealing with urban studies and activities. On prsente une application de la projection azimutale logarithmique dans l'environnement d'un systme d'information municipale (SIM) afin de traiter le problme de la dense concentration de symbolisme thmatique dans une portion restreinte d'un plan de ville, tout en conservant une vue gnrale de la disposition urbaine. On en a fait l'essai sur la cit grecque de Volos, en Thessalie, en effectuant une analyse de type projection   projection ainsi que les tudes de dformation qui s'y apportent. Comme l'exprience le dmontre, l'utilisation de telles projections revªt une importance particulire dans la confection des produits cartographiques sur papier, destins   une varit d'applications: planificateurs urbains, ingnieurs de la circulation, administrateurs municipaux, agents de la scurit publique, archologues, associations professionnelles et autres spcialistes qui tudient l'activit urbaine.
Two New Metrics for Evaluating Pixel-Based Change in Data Sets of Global Extent due to Projection Transformation
Authors: Mulcahy Karen
Published: April 2007

New metrics are introduced for tracking pixel loss and duplication during the transformation of discrete raster data sets by map projection. The metrics, PL and PD, successfully measure pixel loss and pixel duplication, respectively, throughout the spatial realm and provide evidence of the property of equal area. PL and PD are applied to the examination of world equal-area map projections. Traditional map projection distortion evaluation addresses scale, area, shape, and directional distortion, which is appropriate to point-by-point analytical projection methods used for vector data. PL and PD provide an additional means for evaluating map projection distortion for discrete raster data. Data producers and data users, including researchers and policy makers, are often unaware that the choice of a map projection may affect the content of data sets and, possibly, research results. Pixel duplication may be reversed in some cases, but lost pixels mean that data has been lost forever. The results of this work indicate the need for a change in cartographic recommendations for selecting global raster data map projections. The Sinusoid projection, with the greatest angular distortion of the projections studied, would be an unlikely choice for a global equal-area data set, but it exhibits no pixel loss or duplication.
CARTOGRAPHY, ETHICS AND SOCIAL THEORY
Authors: HARLEY JB
Published: April 2007

'Cartography, Ethics and Social Theory' is a sequel to 'Deconstructing the Map' (Cartographica 26 / 2, 1989: 1â€“20) and to the 'Responses' to that paper (see 'Commentary' Cartographica 26 /3 &4, 1989: 89â€“121). It is argued that the absence of a social dimension in cartographic theory has led to a neglect of social issues in the content of maps and that together these deficiencies constitute a crisis of representation. The dilemma of cartographic ethics â€” and the profession's response to it â€” is discussed in the context of the technological transformation in official topographical mapping being induced by the invention of Geographical Information Systems. A case is made for the retention of topographical maps in their present published form on the grounds that they can offer a democratic and humanistic form of geographical knowledge.
Mapping The Great Lakes / The Period Of Imperial Rivalries, 1700−1760
Authors: Heidenreich Conrad E
Published: April 2007

The period under study can be subdivided by the first appearance of Bellin's maps in 1743. Prior to that date, most printed maps were based on the cartography of De l'Isle and Lahontan whose sources of information were derived from material drafted late in the seventeenth century. The manuscript mapping of the first forty years of the eighteenth century treated the peripheral and older settled areas in greater detail than in the previous century. Bellin and D'Anville were the first cartographers to make use of this new material. After the 1740s the original mapping became increasingly focussed on the strategic lower Great Lakes — St. Lawrence — Ohio area. Little of this material was transmitted to European mapmakers. Most of the printed maps after the early 1740s were based on the maps published by Bellin and D'Anville.
One Cartographic View of American Indian Land Areas
Authors: COLE DANIEL G
Published: April 2007

A careful cartographic and geographic scrutiny of anymap frequently reveals errors and design flaws. These problems,together with the amount of spatial generalization required ata given scale, affect how the untutored map reader perceivesand interprets the map. This paper is a self-critical analysis ofthe shortcomings of the U.S. Bureau of Indian Affairs' map,Indian Land Areas. The potential misinterpretations are evaluatedin the context of a discussion concerning the complexAmerican Indian landscape. Un examen minutieux d'une carte révèle souvent desimperfections que ce soit des erreurs géographiques ou encoredes erreurs dûes à la représentation cartographique desphénomènes. Ces problèmes, ainsi que la généralisation cartographiquepar rapport à une échelle donnée, affectent non seulementla perception du lecteur de carte non avisé mais égalementson interprétation de la carte. L'auteur analyse la carte IndianLand Areas produite par le 'U.S. Bureau of Indian Affairs' etsur laquelle il a déjà travaillé. Les imperfections et les faussesinterprétations potentielles sont étudiées en tenant compte de lacomplexité des paysages indiens américains.
The Contribution of Cartography to the Creation of a Dutch Colony and a Chinese State in Taiwan
Authors: ZANDVLIET KEES
Published: April 2007

The maps and charts produced by the brief Dutch colonial government on Taiwan, 1624–1662, follow a clear sequence dictated by changing strategic concerns and contexts that reflected the life-cycle of the colony. First, the Dutch made a general reconnaissance of the island that produced both small-scale charts of the entire coast and large-scale charts of estuaries and natural harbours that might serve as suitable sites for a defensible deep-water harbour. In the second phase, large-scale maps were produced to facilitate military occupation and civil settlement. The Dutch establishment of an agricultural colony in the hinterland of Taiwan created a demand for cadastral and topographical maps requiring the attention of land surveyors, who stayed on the island for extended periods of time.
Traditional Versus Sequenced Choropleth Maps/An Experimental Investigation
Authors: SLOCUM TERRY A , ROBESON SUSAN H , EGBERT STEPHEN L
Published: April 2007

Modern computer technology provides cartographers with a host of new display potentialities not possible with traditional printed maps. One of these is sequencing, or the display of map elements in a particular order. This paper evaluates sequencing of choropleth maps via reaction time experiments with human subjects. Informal experiments reveal that subjects favor some form of sequencing, while formal experiments show no significant difference between traditional and sequenced maps for either information acquisition or memory. Since subjects find sequencing appealing and it does not appear to have negative effects on map learning, software developers may wish to consider including it as part of their cartographic display systems.
CARTOGRAPHY WITHOUT PROGRESS': REINTERPRETING THE NATURE AND HISTORICAL DEVELOPMENT OF MAPMAKING
Authors: EDNEY MATTHEW H
Published: April 2007

This paper extends the current critique of cartography's empiricist presuppositions to the nature of cartography as a practice. After exploring the relevant aspects of empiricist cartography - the manner in which geographic data are treated as constituting a single, monolithic database and the reliance upon a linear and progressive view of cartographic history - a new interpretation of cartography's nature and of its history are presented. Cartography should be seen as a complex amalgam of cartographic modes rather than as a monolithic enterprise. Each mode comprises a set of cultural, social, and technological relations which determine cartographic practices. This conception is applied to modern European cartography in the period between 1500 and 1850, when mapmaking appeared to progress from being an art to being a science (the 'cartographic reformation'). Approaching this period without prior assumptions of progress reveals that cartography's reformation is a myth created by our misunderstanding of the unified mode of Enlightenment cartography, 'mathematical cosmography.' Considering the history of cartography to be the history of the internal changes and external interactions of several modes would appear to be consistent with the complexity of both the historical record and the character of mapmaking as an intellectual, technological, social, and cultural process.
Geographic Information: Its Nature, Classification, and Cartographic Representation
Authors: Forrest David
Published: April 2007

During the development of a cartographic-design expert system, it became apparent that a rigorous classification of the data to be mapped was required. The often-used general classes of points, lines, and areas, and nominal, ordinal, interval, and ratio measurement levels were found to be inadequate for the task. While these provide a useful starting point, detailed examination of the nature and classification of phenomena, spatial, and attribute data to be mapped lead to a more comprehensive set of classes being developed for each of these aspects. The sets of classes are defined and the relationships between them discussed. A set of cartographic-representation methods is described in outline, and the relationship between the data-classification system and the cartographic representations is considered.
TACTUAL MOBILITY MAPS / A COMPARATIVE STUDY
Authors: DACEN NAGEL DIANA L , COULSON MICHAEL R C
Published: April 2007

Tactile maps may be produced in a wide variety of ways and the literature is replete with examples and supporting documentation of each particular method's successful use. The objective of the research reported, was to compare the map use performance of representative methods of tactile map production. The four production methods chosen, were Thermoforming, Multi-textural, Letter Press Plate, and Microcapsule paper. A similar set of four maps representing different levels of complexity was prepared by each technique. Each subject worked with one map at each level of map complexity and with examples of each of the map production methods being compared. The questionnaire comprising both locational and route-finding questions was administered individually to each subject and the time taken to solve each question was recorded as the basis for comparing maps. An unstructured interview was also held to explore each subject's 'feelings' about the maps and their map preference. The results of the study show maps on microcapsule paper recording the fastest times (the best performance). This held not only for the subject group as a whole but also for the subsets of total and partial blindness and by sex. Further, most subjects preferred the microcapsule paper map. In contrast, Thermoformed maps recorded the longest times for correct answers and were not reviewed favourably by the subjects.
Least-cost Path in GIS Using an Accumulated Cost Surface and Slopelines
Authors: DOUGLAS DAVID H.
Published: April 2007

One of the most interesting and potentially useful applications of geographic information systems is the computation over a mapped space of the fastest, shortest, least-cost, or least-impact routes, given a map of the area with its frictions, costs and impediments. The problem is compared to the refraction of light, and a general solution is discussed, with algorithms to implement these. The problem is broken down into the computation of an accumulated cost surface integrated about a destination, and the generation of slope lines, which are the least-cost paths. Examples are presented from the sport of orinteering.
Mapping Time
Authors: Vasiliev Irina
Published: April 2007

Geographic data include locations of places and events, and spatial changes of phenomena. Time is an essential element in tracking changes and in analyzing them to establish patterns, to predict future events, or to explain occurrences. Time information, however, comes in different forms when geographic data are collected. It may be a simple time stamp: the date when a city was incorporated. It may be an expression of duration: how long the forest fires burned. Geographic data may be collected at regular intervals, e.g., the decennial census in the USA. Or they may be recorded only when a change occurs, e.g. a hillside is cut away for development and the change is recorded on the topographic map. Time may be used as a distance measure, and space may be used as a delineator of time. Because of these variations in the uses of time, various types of time information must be understood and the understanding incorporated into methods of producing maps so as to show the information clearly and efficiently.

This research categorizes time as it is used by geographers and as it appears in different forms on maps. The categories are Moments, Duration, Structured Time, Time as Distance, and Space as Clock. Each of these categories defines a particular use of time and provides the basic symbology that is used to represent spatiotemporal information on maps according to the spatial dimensions (point, line, or area) typically available to cartographers.

The framework for the symbolization of temporal information on maps presented in this research establishes two things: the various categories of time found in geography; and the spatial dimensions and symbology available to the cartographer for representing spatiotemporal information on maps.
Atlas Cartography In Prerevolutionary Russia
Authors: CHURKIN V G
Published: April 2007

The author, a specialist in the history of Russian atlas cartography (Tsarist and Soviet), surveys the evolution of prerevolutionary atlases from the simple, crude, general, and unprinted works of the 17th century to the complex, accurate, thematic, and printed works of the 19th century. The making of better atlases was stimulated by Peter the Great's attempts to modernize his country in the early 18th century; the geographic grid replaced the hydrographic network as a base with the amassing of astronomic observations throughout the vast territory of the Russian Empire. In the 19th century private entrepreneurs began to compile atlases, especially school and world atlases. The publication of sector atlases was spurred by the intensification of capitalism during the last half of the 1800's. L'auteur, spécialiste de l'histoire de la cartographie relative à la réalisation des atlas russes – tsaristes et soviétiques – procède à l'étude de l'évolution des atlas établis avant la révolution à partir de manuscrits simples, rudimentaires et généraux du 17e siècle jusqu'aux travaux complexes, précis, thématiques et imprimés du 19e siècle. Pierre Le Grand a encouragé la réalisation d'atlas plus perfectionnés alors qu'il cherchait à moderniser son pays, au début du 18e siècle; le quadrillage géographique a remplacé le réseau hydrographique en tant que base pouvant accumuler des observations astronomiques recueillies au travers du grand territoire de l'Empire russe. Au 19e siècle, le secteur privé a commencé la compilation d'atlas, pour la plupart scolaires et mondiaux. La publication d'atlas de divers secteurs a été grandement encouragée par le renforcement du capitalisme au cours de la seconde moitié du 18e siècle.
A CONCEPTUAL FRAMEWORK AND COMPARISON OF SPATIAL DATA MODELS
Authors: PEUQUET DONNA J
Published: April 2007

This paper examines the major types of spatial data models currently known and places these models in a comprehensive framework. This framework is used to provide clarification of how varying data models, as well as their inherent advantages and disadvantages, are interrelated. It also provides an insight into how these conflicting demands may be balanced in a more systematic and predictable manner for practical applications, and reveals directions for needed future research.
Line Simplification, Geometric Distortion, and Positional Error
Authors: Veregin Howard
Published: April 2007

Line simplification is a generalization method that involves the selective elimination of vertices along a cartographic line. This procedure can introduce positional error by distorting line geometry. This study focuses on the quantification of this distortion with specific reference to the Douglas-Peucker line-simplification algorithm. Results based on US Geological Survey Digital Line Graph (DLG) data for streams and roads show that the algorithm is often suboptimal; that is, the amount of geometric distortion per eliminated vertex is generally not minimized. As the amount of simplification increases, the degree of suboptimality increases in absolute terms but declines in relative terms when compared to the entire distribution of possible distortion values. Significant differences in performance are observed for streams and roads, due to the higher error potential for roads as a function of their geometry.
THE Q'CODE: A SIMPLE SYSTEM FOR SMALL-COMPUTER CODING OF ANTIQUE MAPS
Authors: WILDE GERALD J S
Published: April 2007

The Q'CODEâ„¢ is a set of procedures proposed for the purpose of describing individual geographical and topographic maps, plans and views of historical interest in a short phrase. Its core element or 'call number' consists of a string of 33 characters (letters, digits and blank spaces) and attempts to find an optimal compromise between considerations such as economy of space, readability, absence of ambiguity and adaptability to individual users' needs. The code is fully compatible with personal computers, and available word processing and data base software of all makes. It does not require any programming skills on the part of the user.
CONSIDERATIONS IN PRODUCING SPECIAL MAPS
Authors: BALDOCK E. D.
Published: April 2007

L'auteur expose à grands traits certains éléments de base dont il faut tenir compte avant d'éditer une carte dite "spéciale". Le besoin d'une telle carte devrait tout d'abord, être bien établi, et ses fins exactes précisées. On doit décider préalablement de l'étendue reproduite par la carte, de l'échelle et du contenu du fond de carte. Une attention particulière doit être accordée au système de projection, car il dépend du but de la carte; des considérations pratiques influent toutefois sur la décision finale. Ce mémoire contient des renseignements spécifiques sur certaines projections, dont quatre types classiques sont donnés, en vue d'illustrer les erreurs maximales d'échelle, de superficie, et d'azimut. L'auteur cite, comme autres exemples dans le choix des projections, neuf pays d'Amérique du Sud et centrale dont il indique l'étendue en longitude et en latitude ; il commente les propections convenables pour chaque pays. Il étudie également les questions fondamentales de la représentation par signes conventionnels et des méthode de reproduction.
INTERPOLATION BY CUBIC SEGMENTS WITH NO LOCAL CURVATURE MAXIMA
Authors: WALTON D J , MEEK D S
Published: April 2007

Contour lines may be approximated by cubic splines. However, standard methods for interpolation by cubic splines may result in a curve which intersects itself. The incidence of self-intersections may be greatly reduced by using cubic segments with no local curvature maxima.
A Graphical Introduction to Survey Adjustment
Authors: TOBLER DR. W.
Published: April 2007

It is important that cartographers, and others who use geographic information, understand the procedures used to adjust empirical measurements made for the purpose of specifying locations. Two new graphical interpretations of reconciling distance or directional observations are presented in this paper. These graphics are consistent with standard practice, but treat the problems in a somewhat more general, non-mathematical manner, facilitating understanding. An example is given using driving distances to obtain a map configuration for points in the United States.
Tracking Uncertainty in Derived Height Data
Authors: Gibson J. , Buchheit M.
Published: April 2007

This chapter discusses the tracking of uncertainty in height data derived from stereo imagery that has been obtained from an airborne electro-optical digital multi-spectral imaging system. The overall objective of the software described has been to prepare the data for input into Geographic Information Systems, and to provide the ground coordinates of the data with the greatest accuracy possible. This article has two objectives: to provide a brief overview of the digital imagery procedures used to process the raw imagery and ancillary inertial navigation system data to achieve photogrammetric adjustment, geometric correction, and terrain height extraction, and, second, to illustrate the results of processing a representative data set. One of the final products produced by the software processing systems is a mosaic of ortho-imagery, using the nadir views and the terrain height data generated from the stereo imagery.

The chapter discusses the methods and the procedures that are being developed at the Canada Centre for Remote Sensing for tracking or carrying the absolute and relative accuracies of the derived data products from the raw data through to the final products. The paper concludes with an example of some processed imagery and derived height data along with the confidence measure or uncertainty of the derived height.