Showing papers in "Cartographic Journal in 2006"

Mapping the Results of Geographically Weighted Regression

Abstract: Geographically weighted regression (GWR) is a local spatial statistical technique for exploring spatial nonstationarity. Previous approaches to mapping the results of GWR have primarily employed an equal step classification and sequential no-hue colour scheme for choropleth mapping of parameter estimates. This cartographic approach may hinder the exploration of spatial nonstationarity by inadequately illustrating the spatial distribution of the sign, magnitude, and significance of the influence of each explanatory variable on the dependent variable. Approaches for improving mapping of the results of GWR are illustrated using a case study analysis of population density–median home value relationships in Philadelphia, Pennsylvania, USA. These approaches employ data classification schemes informed by the (nonspatial) data distribution, diverging colour schemes, and bivariate choropleth mapping.

Performance Evaluation of Line Simplification Algorithms for Vector Generalization

Abstract: Many studies of line simplification methods have been developed; however, an evaluation of these methods is still an open issue. This paper aims to evaluate a diversity of automatic line simplification algorithms in terms of positional accuracy and processing time. Past research studies for the performance evaluation were centred on measuring the location difference between a line to be simplified and its simplified version. However, the original line contains positional uncertainty. This paper evaluates performance of the line simplification algorithms using two comprehensive measures of positional accuracy of the simplified line. These two measures include one displacement measure and one shape distortion measure, both of which are able to consider (a) the displacement between the original line and its simplified version, and (b) positional uncertainty of the original line.

Mapping for Wheelchair Users: Route Navigation in Urban Spaces

Abstract: Navigation around urban areas is often constraining for the mobility-impaired due to the fabric of the urban landscape, and there is a need to provide maps tailored to individual abilities. Barriers to effective navigation, such as slope, surface type and dropped kerbs, differ for able-bodied pedestrians and wheelchair users. This study identifies and quantifies such differences, and develops a Geographical Information Systems (GIS) network model for the creation of accessibility maps for wheelchair users. The measurement of barriers uses Digital Elevation Models, calculation of rolling resistance, and surveys in the field using hand-held GIS. A spatial database has been constructed which contains the pedestrian route network and barriers to navigation. A GIS application runs the model, providing a user-friendly interface to define and calculate routes through the pedestrian route network that take account of impedances to accessibility. The model, application and interface has been tested with wheelchair users and the route selection provides a good correspondence with patterns of route finding already established through experience. The interface and individually tailored maps generated, provide a tool suitable to assist wheelchair users new to an area; to enable better navigation for existing users, and a means for planners to consider the way in which access is restricted for wheelchair users in their designs for more inclusive urban environments.

Measuring map complexity

Abstract: In this paper, issues of complexity and their application to cartographic practice and enquiry are addressed After an initial discussion of the nature of complexity and its fitful study in cartography over recent years, an assessment is made of the potential for quantifying map complexity A series of practical tests was devised and is described These consider a wide range of metrics, including spatial statistical measures, entropy and image-based indices Their application to both raster and vector mapping is investigated Data compression shows promise as an index which can be used to characterize the graphical variation within the map face The nature of digital data compression is described, with reference to raster map representations, and it is determined that a data-compression ratio can act as a simple and effective complexity measure The paper concludes by listing some of the reasons why complexity, as measured by data compression, could be used in cartographic practice

Swiss-Style Colour Relief Shading Modulated by Elevation and by Exposure to Illumination

Abstract: Maps with coloured relief shading, modulated by elevation and by exposure to illumination, present topography in a particularly vivid and descriptive manner. Carefully modulated illumination and shading shown in continuous colour tones simulate the third dimension of topography, helping map-readers to conceive more easily the terrain's important landforms. Since the end of the 19th century, cartographers have developed a wide variety of colour schemes. The first part of this paper illustrates the graphical and technical developments of the past, leading to Swiss-style coloured relief shading; the second part presents a new computer-based method for colourizing grey-shaded relief inspired by classic colour schemes. The method uses a colour look-up table and a digital elevation model. The colour look-up table has colours for all combinations of initial grey values and terrain elevations. It is constructed from interactively placed colour reference points.

The Palestine Exploration Fund Map (1871-1877) of the Holy Land as a Tool for Analysing Landscape Changes: the Coastal Dunes of Israel as a Case Study

Abstract: The Palestine Exploration Fund (PEF) maps (1871–1877) are highly praised for their accuracy and completeness; however, no systematic analysis of their accuracy has been done to date. To study the potential of these 1:63,360 maps for a quantitative analysis of land cover changes over a period of time, I have compared them to 20th century topographic maps. The map registration error of the PEF maps was 74.4 m using 123 control points of trigonometrical stations and a 1st order polynomial. The median RMSE of all control and test points (n = 1104) was 153.6 m. As a case study of land cover changes, the area of coastal dunes as shown on the PEF maps was compared with that shown on British Mandate 1:20,000 topo-cadastral maps from c. 1930. In five of the six areas analysed, the yearly dunes movement rate was above the estimated annual error due to data resolution (2.96 m/year). The rate of dune movement south of Acre was found to be between 3.9 and 6.3 m/year (depending on the method used for map regist...

Specialist Maps Prepared by British Military Geologists for the D-Day Landings and Operations in Normandy, 1944

Abstract: During the Second World War, British military geologists assisted planning for the Allied liberation of Normandy by generating specialist maps – supporting the greatest amphibious operation in worl...

Why maps matter in GIScience

Abstract: or Real An important characteristic of maps is the fact that they represent selections from reality in an abstract way. Especially for presentation purposes, maps that look ‘empty’ might even work better than maps with an overloaded view. In an exploratory mode, an overloaded map could be very representative for the topic being studied, and via interactive selection and filtering techniques the user can ‘drill-down’ to the information thought relevant (Shneiderman, 1998). The ‘selection/abstraction’ characteristic is not only challenged by exploration, but also by new viewing environments such as virtual and augmented reality (VR and AR) (Dykes et al., 1999a; Unwin and Fisher, 2001; Sherman and Craig, 2002). These allow a different view on reality and, in addition, one can become completely absorbed in this ‘reality’. VR and AR require realism in the imagery used, which can be obtained via state of the art data collection techniques, such as laser scanning 86 The Cartographic Journal

Mapping Golf: A Contextual Study

Abstract: A contextual study of the employment of golf mapping reveals the diversity of products, designs and uses. This research describes the different roles played by a very specialized range of products employed on and off the golf course and places them in social, historical and technological contexts. It argues for a relational approach to mapping as a process, based upon a wide investigation of practice, rather than a narrow focus on design, cognition or technology. Grounded in Actor-Network Theory, this approach reveals a complex web of links between producers, users, representations and meanings.

An Algorithm for Localised Contour Removal over Steep Terrain

Abstract: Isolines have proved to be a highly effective way of conveying the shape of a surface (most commonly in the form of height contours to convey geographical landscape). Selecting the right contour interval is a compromise between showing sufficient detail in flat regions, whilst avoiding excessive crowding of lines in steep and morphologically complex areas. The traditional way of avoiding coalescence and confusion across steep regions has been to manually remove short sections of intermediate contours, while retaining index contours. Incorporating humans in automated environments is not viable. This research reports on the design, implementation and evaluation of an automated solution to this problem involving the automatic identification of coalescing lines, and removal of line segments to ensure clarity in the interpretation of contour information. Evaluation was made by subjective comparison with Ordnance Survey products. The results were found to be very close to the quality associated with man...

Epistemology of Geopolitical Atlases from the 1980s to the Early 2000s

Abstract: Since the early 1980s, we have seen a new influx of numerous geopolitical atlases. They have been produced to meet society's implicit need to fix the boundaries of international issues and the relationships of force between the various powers. These atlases clearly express established ideologies and allow us to determine various trends of thought; messages which the authors wish us to take on board by studying cartographic themes. This is the approach we will be taking in this article.In this paper, we aim to show the epistemological development of geopolitical atlases. The first part of the article gives the general outline of the epistemological development of geopolitical atlases, in which two main periods stand out. The first corresponds with the 1980s, which can be described as a realist decade. The state was a geopolitical player that could not be overlooked within a bipolar world; maps showing conflicts between the two major powers and thematic maps showing an ideological clash between them...

Effect of Generalization on Area Features: A Comparative Study of Two Strategies

Abstract: The generalization of area features is a very important topic in digital map generalization, particularly in thematic map generalization. The operations used in area generalization, will cause changes in the geometry and thematic attributes of area features and the topological relationships between them. Very limited quantitative measures, especially for semantics, are available to describe the effect of generalization when multiple objects are involved or when the entire map needs to be characterized. Therefore, the aim of this study is to provide some quantitative measures for the changes (especially in semantics) that have occurred during generalization. A set of quantitative measures of data quality, i.e. accuracy, consistency, and completeness, has been developed to assess such effects. The effect of generalization on area features are compared between two approaches, geometry-based merging and theme-based aggregation. An experimental test has also been carried out to illustrate their differences in terms of the proposed quality measures, which demonstrates the practical usefulness of these measures.

Cataloguing Electronic Cartographic Materials: Standard Cataloguing

Abstract: The author describes the cataloguing of electronic cartographic materials according to the international standards published in the Anglo-American Cataloguing Rules, 2nd revised edition, and the MARC21 format. Guidance on the special interpretation of fields found in records for all cartographic materials, as well as instructions for completing those fields used specifically for electronic formats are given. The different MARC21 fields are itemized and an example of a complete catalogue record for an electronic resource are provided.

The Road to a World Heritage Monument for Surveyors

Abstract: In July 2005 UNESCO voted to have the Struve Geodetic Arc inscribed on its List of World Heritage Monuments. Not only is this a first for the Surveying profession, but also for UNESCO in the sense of the type of monument it lists. This paper will outline the background to Arc measurement, give some details of the Struve Arc and its possible extension into Africa and indicate why it is not for the faint hearted to get involved in putting a monument of any sort up for UNESCO listing.

The Journal of Maps: Rationale for Its Establishment and Review of Initial Operations

Abstract: (2006). The Journal of Maps: Rationale for Its Establishment and Review of Initial Operations. The Cartographic Journal: Vol. 43, No. 1, pp. 90-96.

'Be Map Aware: Cutting-edge…Not Close to the Edge'

Abstract: No sooner had the last issue of The Cartographic Journal hit the shelves than yet another example of poor cartography was highlighted in the media. Drivers using in-car navigation systems to travel from Swaledale to Wensleydale in the Yorkshire Dales National Park, UK, were being ‘recommended’ to drive through the village of Crackpot perilously close to the edge of a 100 ft cliff. Once it became clear that the track was impassable, or they became stuck, drivers were reversing and risked plunging over the cliff edge. The media reported this in a humorous way yet for the drivers the experience must have been somewhat different. As a cartographer, my response was also different; it is fast becoming a theme in my editorials that whilst we are seeing more mapping and digital spatial data in mainstream use than ever before, quality is eroding rapidly. Yes, sometimes mapping errors are humorous but this example illustrates clearly that there are potentially serious implications. Maps have always had the potential to ‘lie’ but some lies are worse than others. It also serves to remind us of the importance of correct and effective representation of the world around us so that map users have confidence in what they are using; and confidence in the people who develop map products of whatever form. The short-cut through Crackpot may be regarded as a metaphor for modern cartography. The rapid development of technology has for too long promised to take us to exciting places but, in many ways, has constrained us to a narrow path ahead. Along the path are littered the remains of institutions that followed the path with good intent, but which fell by the wayside as interest declined and technology created a cartographic by-pass. There is, however, no short-cut to good cartographic design and the preparation of effective mapping. There is no getting away from the impact of technology but a rules-based approach cannot substitute for the application of sound cartographic principles. There is every opportunity to recapture the discipline from those who seem to be unaware of the very real impact poor mapping has; to promote good mapping and a love of maps; to reeducate and make clear the importance of maps. The British Cartographic Society is at the forefront of the Better Mapping campaign and is establishing a number of initiatives to promote good cartography recently announced by the BCS president, Seppe Cassettari. I echo Seppe’s message and encourage BCS members and Journal readers to participate; to take up the challenges set; and to contribute in whatever way you can so that we don’t end up reversing off the cliff. The Cartographic Journal has an important role to play on the road ahead. In particular, I encourage readers to submit their own work for publication in these pages to maintain and develop the journal’s standard and reputation. The Journal has a wide international readership of likeminded people and contains interesting, cutting-edge papers on a diverse range of cartography related research and opinion. What we have to do is take the message beyond these pages. You can easily help re-educate and promote by inviting a colleague or friend to read an article from The Journal. Agreed, some may find certain articles not to their taste but you simply have to flick through the last few issues and I’m certain there will be something of interest to a wider general readership. This approach will give people an insight into what it means to be involved in the mapping sciences and why cartographers are passionate about what they do. This issue of The Journal yet again provides ample proof of the breadth of cartographic research. We begin with a paper by Ted Rose et al. on the preparation of specialist maps by British military geologists in support of the 1944 D-Day landings. The wide variety of scales and map types illustrates with clarity the importance that a range of maps gives and that in these circumstances, at least, no single map has the capacity to provide a basis for good decision-making. The paper contributes to a growing literature on mapping generated during World War II and follows up Ted’s well received paper on specialist mapping of the Channel Islands prepared by German military geologists recently published in The Journal. Both papers are excellent and well researched examples of historical cartography and show that there is much to be discovered by examining maps of the past. William Mackaness and Mike Steven tackle a cartographic design issue that arises from the inevitable conflict between map scale and the detail of contour representation. In areas of steep terrain, coalescence of contour lines has traditionally been avoided through judicious manual removal of intermediate contours. As we have recognized more widely, technology can be both prohibitive as well as offering new and exciting opportunities, but this is an area where it has been difficult to create an automated approach that can apply the same standard of generalization as a human. In this paper, the author’s recognize the need to develop methods for automated identification of coalescing linework and line removal in order to make automated The Cartographic Journal Vol. 43 No. 2 pp. 115–116 July 2006 # The British Cartographic Society 2006

Effective Mapping: The Emergence of the Large Yellow Splat!

Abstract: This first issue of 2006 follows an extremely well received Map Curators’ Group Special Issue of The Cartographic Journal. The Special Issue received considerable praise from readers and it is only proper that I extend my thanks to guest editor Anne Taylor, and contributors, on what was a stimulating collection of articles pertinent to historical and contemporary map librarianship. Articles of the ‘whither?’ variety were combined successfully with others that examined the mechanics of the discipline. As one reader noted, nothing in this field stands still for very long yet the Special Issue will remain for some years essential reading for those in the profession and also those considering joining it. I am pleased to announce that Anne has agreed to join the Editorial Board of The Journal despite what she reported as being a ‘never again’ experience. This being my first full issue as Editor, I am fast learning of the difficulties of editorship; namely the non-stop paper chase, keeping track of the review process, keeping authors and reviewers updated and ensuring I hit the publication deadline. One reader noted that the Special Issue was, indeed, published in December as per the cover which is testament not only to Anne’s efforts but the efforts of the previous editor, Peter Vujakovic. I sincerely hope that you read this in March, as intended. At one point this issue seemed a long way off and, for a while, I thought I might have to write the journal as well as edit it! Compiling The Journal is a logistical headache at times and it was with regret that a paper had to be removed from the Special Issue at the last minute in order to meet publication requirements. It is therefore with immense gratitude that I thank the author, Mary Larsgaard, for being understanding and allowing us to hold over her paper and publish it in this issue instead. Mary’s paper in the Special Issue examined various metadata standards and explored the cataloguing of geospatial data. Her companion paper, presented here, describes the cataloguing of electronic cartographic materials and the MARC21 format and should be considered a continuation of the Special Issue in every sense. The remainder of this issue once again illustrates the diversity of work that drives our various cartographic interests. Wenzhong Shi and ChuiKwan Cheung have been involved in a number of studies relating to automated cartographic line simplification and note that many techniques remain poorly evaluated. Their paper on evaluating the performance of line simplification for vector generalisation provides a timely assessment of a variety of different approaches. Accuracy is also the focus of Noam Levin’s examination of The Palestine Exploration Fund (PEF) maps (1871–1877) as a tool for assessing landscape change. Nowhere is the diversity of cartography more in evidence than in these two papers; both deal with the central issue of accuracy of cartographic representation but triggered by completely different approaches and interests. Shi and Cheung’s contemporary evaluation of various algorithms contrasts dramatically with Levin’s use and examination of historical documents but it is pleasing that breadth in cartographic research is thriving. The final refereed paper in this issue, by Linda Beale et al., is a detailed examination of the way in which wheelchair users are hindered in their navigation through urban landscapes and the development of a tool to create bespoke accessibility maps using network modelling in GIS. As my former lecturer (Roger Anson, Oxford Polytechnic) reminded us in practically every lecture, cartographer’s should foremost have the user in mind when designing maps for effective communication. This holds as true today as when we were sat listening to Roger’s wise words. However, with technological developments in digital mapping, GIS, and internetserved maps it strikes me that this important, defining principle is all too easily overlooked. The conceptual detail that underpins Beale et al.’s work evidences the care that should be taken in putting the user at the heart of the creation of any cartographic product. The focus of my Editorial in last year’s July issue of The Cartographic Journal focussed on the contrast between the increased prevalence of maps in every day use and the seemingly persistent decline in their quality and function – maps often made by people with little or no training, constructed with ever more complex software yet which evidence a poor appreciation of their complexity, design and purpose. As if to provide me with greater cause for consternation on this theme I recently had the misfortune of having to look at the most absurd in-flight map. Normally, the maps displayed on the small screens in the back of the seat in front of you on an aircraft are useful to pass the time and monitor the progress of your flight. They generate nothing more The Cartographic Journal Vol. 43 No. 1 pp. 3–4 March 2006 # The British Cartographic Society 2006

'Getting Your Feet Wet: Designing Soggy Blue Lines Effectively'

Abstract: My trusty alarm clock woke me at its usual time this morning. The radio sparked into life which is the signal to attempt to do likewise. This morning was slightly different. It is not every day that you wake to a cartographic news item on the early morning news so my attention was immediately focussed. It transpired that I was listening to a report of a survey on the map-reading skills of young motorists. Half of all young drivers are unable to read a road map; two-thirds of those age 18–34 did not know that an A road on a standard printed road map is coloured red; and nearly a third of those surveyed confused the M40 for the River Avon (well, it is blue after all!). Furthermore, 14% of all motorists admitted to never using a paper-based road atlas and this figure rose to 20% for drivers aged below 35. I am not entirely sure what these statistics prove. Such surveys are rarely based on sound survey design and sampling and, of course, the figures have gone through the inevitable filter of the commissioning organisation and the media before being offered to the public over the airwaves. However, the purpose seemed to be to illustrate the negative impact that the rapid rise in in-car satellite navigation has had on map-reading skills. Such research is to be applauded. The British Cartographic Society has been saying the same for some time now; that increasing mis-use of digital spatial data and GIS users (with little idea how to design effective mapping) have been partly to blame for the decline in cartography as a discipline and a profession as well as a dumbing down of map literacy in general. Now we have statistics to prove it so we can relax in the knowledge we were right all along and carry on. Is that really the message though, and can we really ignore it? What proportion of people would have answered the questions correctly 5, 10, 20 years ago? Was there ever a time when everyone had a road atlas in their glove-box and knew how to use it properly? I suspect that the results of the survey would not have been substantially different had it been carried out 10 years ago. Road maps have always been fair game in a world where people will blame anything other than their own poor navigational ability, spatial awareness and lack of route planning in getting from A to B. The poor old map has always borne the brunt of the motorist’s limitations and, anyway, rivers and roads are both coloured blue on many road atlases! So in many ways my reaction to the survey is different. As cartographers, we might search to improve the depiction of roads on printed road atlases to attempt to account for the way in which people use them (or not). However, finding an effective mechanism that everyone can immediately interpret remains a major stumbling block because no two map users are the same. They are drivers and no two drivers will have the same map-reading skills and spatial understanding so we simply cannot expect them to be able to use maps equally successfully. You can lead a horse to water but... It is therefore a bit unfair to be overly critical of the rise in in-car navigational aids (or any other digital device that delivers map products) and their apparent impact on map-reading. Statistics can always be used to support a multitude of arguments! It might be argued that if more drivers are using such tools then more people are using cartographic products which might improve spatial understanding and, eventually, map-reading and the appreciation of maps. If many road-users are reluctant to use or own a printed road atlas then doesn’t SAT-NAV actually bring more people into contact with cartographic products? OK, it may not be the traditional dogeared road atlas that lurks underneath a pile of detritus in the foot-well of the rear passenger seat but that is no bad thing. That precise image of the road atlas as being an object of derision and an object that one would only consult as a last resort is something that we might never overcome. My last editorial noted the potential problems caused by such digital navigational aids taking us down the wrong path but, in many ways, this sort of technological development and new medium for delivering maps to a mass audience (it has pretty, moving pictures so it makes it fun!) can only increase interest in maps and replace the somewhat unfair image that the paper map holds for some. If the excitement of gadgetry is leading to a rise in people’s experience of spatial information and maps then that can only be beneficial to their map literacy. It is also of benefit to cartography but it does mean we have to engage in the effective design of digital map products in whatever digital environments we use to create them. It would be sad to see the end of the traditional road atlas but I suspect many cartographers might even have to admit to having one that is considerably out-of-date and currently ‘lost’ somewhere in their car. Rather than hang on doggedly to the past The Cartographic Journal Vol. 43 No. 3 pp. 193–197 December 2006 # The British Cartographic Society 2006

National mapping on a small island : geographical information and cartographic development in Malta

Abstract: The National Mapping Agency (NMA) in Malta is part of the Malta Environment and Planning Authority (MEPA). Geographical data and information is a key component of business processes within MEPA. Spatial and attribute data is widely disseminated to the public over the internet and open access to information is considered one of the key values of the organization. This paper provides a brief history of the NMA, its role and response to changing data needs, product development and political change. It explores some of the issues that affect cartography in a small island nation. The NMA was set up in 1988 and, although relatively young by most national mapping agency standards, it has undergone considerable organizational change during its near 20 year existence (Table 1). Coupled with this has been the rapid development of Geographical Information Systems (GIS) and digital cartography which the agency has had to embrace and develop. There have been a number of major changes in both the organizational structure and the way in which geographical data and cartography has been incorporated. In general, changes reflect the many strategic decisions taken at different stages that include upgrades to the information systems available at the time. There have, however, been three key phases of development that have resulted in major structural changes and a new modus operandi, namely the inception of the NMA (1988); the forming of a new organization (1992); and the amalgamation of two organizations (2002). At each stage the remit of the Mapping Unit has been broadened to widen the scope of its operations and further integrate key components of MEPA. For instance, new planning legislation has brought with it new information needs and the recent accession to the European Union has resulted in the imposition of new EUreporting requirements. Data sources have changed considerably over the last 20 years. Figures 1 to 4 shows the harbour area in Valletta and provide a contrast between original military surveys, datasets derived photogrammetrically from 1998 aerial photographs, 2004 aerial photographs and the most current digital data product – the 2004 digital orthophoto of Malta. These images represent the various developmental stages that have shaped the work of the NMA. As the organization has changed, so have its products resulting from improvements in data capture, image resolution, colour and technological change. At a structural level, change in the organization created new demands for more detailed imagery and uniform coverage of the island. Initially, all mapping tasks were carried out at the British Ordnance Survey. This was superseded by a move to IGN France shortly followed by a move of all mapping tasks to offices in Malta itself, with MEPA carrying out the whole mapping process including the out-sourcing of digital image acquisition through analysis to output. Organizational change has also led to a planned programme of training and skills development initiatives (Gatt and Stothers, 1996). One initiative has seen several of the core staff in the NMA recently completing the UNIGIS distance learning MSc course in GIS. Staff prepared MSc theses on a range of planning and geo-spatial data issues pertinent to the Maltese Islands which have also assisted in shaping GI-related change (Formosa, 2000; Agius, 2003; Valentino, 2004; Conchin, 2005). The research carried out through the studies has enhanced the technical and organizational aspects of dealing with spatial data, influencing the whole mapping process and integration of the process within ISO standardization, and aiding the implementation of new techniques such as the creation of bespoke map-servers and web-technologies.