The Experts below are selected from a list of 10971 Experts worldwide ranked by ideXlab platform
Bernhard Jenny - One of the best experts on this subject based on the ideXlab platform.
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a guide to selecting Map Projections for world and hemisphere Maps
2017Co-Authors: Bernhard Jenny, Bojan Savric, Nicholas D Arnold, Brooke E Marston, Charles A PreppernauAbstract:Selecting the most suitable projection can be challenging, but it is as essential a part of cartographic design as color and symbol selection and should be given the same degree of consideration. A poorly chosen projection can result in misinterpreted information and impact the effectiveness of a Map. This chapter provides guidance in selecting Projections for world and hemisphere Maps.
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combining world Map Projections
2017Co-Authors: Bernhard Jenny, Bojan SavricAbstract:Cartographers have developed various techniques for deriving new Projections from existing Projections. The goal of these techniques is to substitute a disadvantageous trait of one of the source Projections with the second source projection. This chapter discusses creating new Projections by the juxtaposition and blending of two existing Projections. It also presents a new approach for selectively combining projection characteristics. The emphasis in this chapter is on Projections for world Maps, as the described techniques are most useful for this scale.
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projection wizard an online Map projection selection tool
Cartographic Journal, 2016Co-Authors: Bojan Savric, Bernhard Jenny, Helen JennyAbstract:The selection of Map Projections is difficult and confusing for many. This article introduces Projection Wizard, an online Map projection selection tool available at projectionwizard.org that helps Mapmakers select Projections. The user selects the desired distortion property, and the area to be Mapped on an interactive web Map. Projection Wizard then proposes a projection, along with projection parameters (such as standard parallels). The tool also creates a preview Map with the proposed projection, and provides the corresponding projection code in PROJ.4 format, if applicable. The automated selection process is based on John P. Snyder's selection guideline with a few adjustments. This article discusses the automated selection process, and the Map Projections suggested. Projection Wizard solves the problem of Map projection selection for many applications and helps cartographers and GIS users choose appropriate Map Projections.
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automating the selection of standard parallels for conic Map Projections
Computers & Geosciences, 2016Co-Authors: Bojan Savrio, Bernhard JennyAbstract:Conic Map Projections are appropriate for Mapping regions at medium and large scales with east-west extents at intermediate latitudes. Conic Projections are appropriate for these cases because they show the Mapped area with less distortion than other Projections. In order to minimize the distortion of the Mapped area, the two standard parallels of conic Projections need to be selected carefully. Rules of thumb exist for placing the standard parallels based on the width-to-height ratio of the Map. These rules of thumb are simple to apply, but do not result in Maps with minimum distortion. There also exist more sophisticated methods that determine standard parallels such that distortion in the Mapped area is minimized. These methods are computationally expensive and cannot be used for real-time web Mapping and GIS applications where the projection is adjusted automatically to the displayed area. This article presents a polynomial model that quickly provides the standard parallels for the three most common conic Map Projections: the Albers equal-area, the Lambert conformal, and the equidistant conic projection. The model defines the standard parallels with polynomial expressions based on the spatial extent of the Mapped area. The spatial extent is defined by the length of the Mapped central meridian segment, the central latitude of the displayed area, and the width-to-height ratio of the Map. The polynomial model was derived from 3825 Maps-each with a different spatial extent and computationally determined standard parallels that minimize the mean scale distortion index. The resulting model is computationally simple and can be used for the automatic selection of the standard parallels of conic Map Projections in GIS software and web Mapping applications.
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the natural earth ii world Map projection
International Journal of Cartography, 2015Co-Authors: Bojan Savric, Tom Patterson, Bernhard JennyAbstract:The Natural Earth II projection is a new compromise pseudocylindrical projection for world Maps. The Natural Earth II projection has a unique shape compared to most other pseudocylindrical Projections. At high latitudes, meridians bend steeply toward short pole lines resulting in a Map with highly rounded corners that resembles an elongated globe. Its distortion properties are similar to most other established world Map Projections. Equations consist of simple polynomials. A user study evaluated whether Map-readers prefer Natural Earth II to similar compromise Projections. The 355 participating general Map-readers rated the Natural Earth II projection lower than the Robinson and Natural Earth Projections, but higher than the Wagner VI, Kavrayskiy VII and Wagner II Projections.
Philippe De Maeyer - One of the best experts on this subject based on the ideXlab platform.
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the influence of Map Projections on people s global scale cognitive Map a worldwide study
ISPRS international journal of geo-information, 2020Co-Authors: Lieselot Lapon, Kristien Ooms, Philippe De MaeyerAbstract:Map Projections are required to represent the globe on a flat surface, which always results in distorted representations of the globe. Accordingly, the world Maps we observe in daily life contexts, such as on news sites, in news bulletins, on social media, in educational textbooks or atlases, are distorted images of the world. The question raises if regular contact with those representations of the world deforms people’s global-scale cognitive Map. To analyze people’s global-scale cognitive Map and if it is influenced by Map Projections, a short playful test was developed that allowed participants to estimate the real land area of certain regions, countries, and continents. More than 130,000 people worldwide participated. This worldwide dataset was used to perform statistical analyses in order to obtain information on the extent that Map Projections influence the accuracy of people’s global-scale cognitive Map. The results indicate that the accuracy differs with the Map projection but not to the extent that one’s global-scale cognitive Map is a reflection of a particular Map projection.
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the influence of the web mercator projection on the global scale cognitive Map of web Map users
Conference On Spatial Information Theory, 2017Co-Authors: Lieselot Lapon, Kristien Ooms, Philippe De MaeyerAbstract:For decades, cartographers and cognitive scientists have been speculating about the influence of Map Projections on mental representations of the world. We investigate if the mental Map of young people is influenced by the increasing availability of web Maps and its Web Mercator projection. An application is developed to let participants scale the area of some regions compared to Europe. The outcome gives insight into implications of using a—potentially misleading—Map projection on the global-scale cognitive Map.
Lorenz Hurni - One of the best experts on this subject based on the ideXlab platform.
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the light source metaphor revisited bringing an old concept for teaching Map Projections to the modern web
ISPRS international journal of geo-information, 2019Co-Authors: Magnus Heitzler, Hansrudolf Bar, Roland Schenkel, Lorenz HurniAbstract:Map Projections are one of the foundations of geographic information science and cartography. An understanding of the different projection variants and properties is critical when creating Maps or carrying out geospatial analyses. The common way of teaching Map Projections in text books makes use of the light source (or light bulb) metaphor, which draws a comparison between the construction of a Map projection and the way light rays travel from the light source to the projection surface. Although conceptually plausible, such explanations were created for the static instructions in textbooks. Modern web technologies may provide a more comprehensive learning experience by allowing the student to interactively explore (in guided or unguided mode) the way Map Projections can be constructed following the light source metaphor. The implementation of this approach, however, is not trivial as it requires detailed knowledge of Map Projections and computer graphics. Therefore, this paper describes the underlying computational methods and presents a prototype as an example of how this concept can be applied in practice. The prototype will be integrated into the Geographic Information Technology Training Alliance (GITTA) platform to complement the lesson on Map Projections.
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graphical design of world Map Projections
International Journal of Geographical Information Science, 2010Co-Authors: Bernhard Jenny, Tom Patterson, Lorenz HurniAbstract:The design of new Map Projections has up until now required mathematical and cartographic expertise that has limited this activity to a small group of specialists. This article introduces the background mathematics for a software-based method that enables cartographers to easily design new small-scale world Map Projections. The software is usable even by those without mathematical expertise. A new projection is designed interactively in an iterative process that allows the designer to graphically and numerically assess the graticule, the representation of the continents, and the distortion properties of the new projection. The method has been implemented in Flex Projector, a free and open-source application enabling users to quickly create new Map Projections and modify existing Projections. We also introduce new tools that help evaluate the distortion properties of Projections, namely a configurable acceptance index to assess areal and angular distortion, a derived acceptance visualization, and interactive profiles through the distortion space of a projection. To illustrate the proposed method, a new projection, the Cropped Ginzburg VIII projection, is presented.
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Flex projector-interactive software for designing world Map Projections
Cartographic Perspectives, 2008Co-Authors: Bernhard Jenny, Tom Patterson, Lorenz HurniAbstract:Flex Projector is a free, open-source, and cross-platform software application that allows cartographers to interactively design custom Projections for small-scale world Maps. It specializes in cylindrical, and pseudocylindrical Projections, as well as polyconical Projections with curved parallels. Giving meridians non-uniform spacing is an option for all classes of Projections. The interface of Flex Projector enables cartographers to shape the projection graticule, and provides visual and numerical feedback to judge its distortion properties. The intended users of Flex Projector are those without specialized mathematical expertise, including practicing Mapmakers and cartography students. The pages that follow discuss why the authors developed Flex Projector, give an overview of its features, and introduce two new Map Projections created by the authors with this new software: the A4 and the Natural Earth projection.
Bojan Savric - One of the best experts on this subject based on the ideXlab platform.
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a guide to selecting Map Projections for world and hemisphere Maps
2017Co-Authors: Bernhard Jenny, Bojan Savric, Nicholas D Arnold, Brooke E Marston, Charles A PreppernauAbstract:Selecting the most suitable projection can be challenging, but it is as essential a part of cartographic design as color and symbol selection and should be given the same degree of consideration. A poorly chosen projection can result in misinterpreted information and impact the effectiveness of a Map. This chapter provides guidance in selecting Projections for world and hemisphere Maps.
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combining world Map Projections
2017Co-Authors: Bernhard Jenny, Bojan SavricAbstract:Cartographers have developed various techniques for deriving new Projections from existing Projections. The goal of these techniques is to substitute a disadvantageous trait of one of the source Projections with the second source projection. This chapter discusses creating new Projections by the juxtaposition and blending of two existing Projections. It also presents a new approach for selectively combining projection characteristics. The emphasis in this chapter is on Projections for world Maps, as the described techniques are most useful for this scale.
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projection wizard an online Map projection selection tool
Cartographic Journal, 2016Co-Authors: Bojan Savric, Bernhard Jenny, Helen JennyAbstract:The selection of Map Projections is difficult and confusing for many. This article introduces Projection Wizard, an online Map projection selection tool available at projectionwizard.org that helps Mapmakers select Projections. The user selects the desired distortion property, and the area to be Mapped on an interactive web Map. Projection Wizard then proposes a projection, along with projection parameters (such as standard parallels). The tool also creates a preview Map with the proposed projection, and provides the corresponding projection code in PROJ.4 format, if applicable. The automated selection process is based on John P. Snyder's selection guideline with a few adjustments. This article discusses the automated selection process, and the Map Projections suggested. Projection Wizard solves the problem of Map projection selection for many applications and helps cartographers and GIS users choose appropriate Map Projections.
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the natural earth ii world Map projection
International Journal of Cartography, 2015Co-Authors: Bojan Savric, Tom Patterson, Bernhard JennyAbstract:The Natural Earth II projection is a new compromise pseudocylindrical projection for world Maps. The Natural Earth II projection has a unique shape compared to most other pseudocylindrical Projections. At high latitudes, meridians bend steeply toward short pole lines resulting in a Map with highly rounded corners that resembles an elongated globe. Its distortion properties are similar to most other established world Map Projections. Equations consist of simple polynomials. A user study evaluated whether Map-readers prefer Natural Earth II to similar compromise Projections. The 355 participating general Map-readers rated the Natural Earth II projection lower than the Robinson and Natural Earth Projections, but higher than the Wagner VI, Kavrayskiy VII and Wagner II Projections.
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user preferences for world Map Projections
Cartography and Geographic Information Science, 2015Co-Authors: Bojan Savric, Bernhard Jenny, Denis White, Daniel R StrebeAbstract:Many small-scale Map Projections exist, and they have different shapes and distortion characteristics. World Map Projections are mainly chosen based on their distortion properties and the personal preferences of cartographers. Very little is known about the Map projection preferences of Map-readers; only two studies have addressed this question so far. This article presents a user study among Map-readers and trained cartographers that tests their preferences for world Map Projections. The paired comparison test of nine commonly used Map Projections reveals that the Map-readers in our study prefer the Robinson and Plate Carree Projections, followed by the Winkel Tripel, Eckert IV, and Mollweide Projections. The Mercator and Wagner VII Projections come in sixth and seventh place, and the least preferred are two interrupted Projections, the interrupted Mollweide and the interrupted Goode Homolosine. Separate binominal tests indicate that Map-readers involved in our study seem to like Projections with straight rather than curved parallels and meridians with elliptical rather than sinusoidal shapes. Our results indicate that Map-readers prefer Projections that represent poles as lines to Projections that show poles as protruding edges, but there is no clear preference for pole lines in general. The trained cartographers involved in this study have similar preferences, but they prefer pole lines to represent the poles, and they select the Plate Carree and Mercator Projections less frequently than the other participants.
Lieselot Lapon - One of the best experts on this subject based on the ideXlab platform.
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the influence of Map Projections on people s global scale cognitive Map a worldwide study
ISPRS international journal of geo-information, 2020Co-Authors: Lieselot Lapon, Kristien Ooms, Philippe De MaeyerAbstract:Map Projections are required to represent the globe on a flat surface, which always results in distorted representations of the globe. Accordingly, the world Maps we observe in daily life contexts, such as on news sites, in news bulletins, on social media, in educational textbooks or atlases, are distorted images of the world. The question raises if regular contact with those representations of the world deforms people’s global-scale cognitive Map. To analyze people’s global-scale cognitive Map and if it is influenced by Map Projections, a short playful test was developed that allowed participants to estimate the real land area of certain regions, countries, and continents. More than 130,000 people worldwide participated. This worldwide dataset was used to perform statistical analyses in order to obtain information on the extent that Map Projections influence the accuracy of people’s global-scale cognitive Map. The results indicate that the accuracy differs with the Map projection but not to the extent that one’s global-scale cognitive Map is a reflection of a particular Map projection.
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the influence of the web mercator projection on the global scale cognitive Map of web Map users
Conference On Spatial Information Theory, 2017Co-Authors: Lieselot Lapon, Kristien Ooms, Philippe De MaeyerAbstract:For decades, cartographers and cognitive scientists have been speculating about the influence of Map Projections on mental representations of the world. We investigate if the mental Map of young people is influenced by the increasing availability of web Maps and its Web Mercator projection. An application is developed to let participants scale the area of some regions compared to Europe. The outcome gives insight into implications of using a—potentially misleading—Map projection on the global-scale cognitive Map.