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Results for “Cartographica: The International Journal for Geographic Information and Geovisualization”

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6 recordsLinked to original sources
USGS1982

The modified polyconic projection for the IMW

The modified Polyconic map projection designed by Lallemand and adopted for the International Map of the World between 1909 and 1962 has two meridians and two parallels which are true to scale. Constructed geometrically in the past, forward and inverse coordinate transformations may be calculated analytically in order to transfer data from existing quadrangles to other maps. The equations for these transformations are derived and used to calculate representative tables of coordinates andscale factors. Although the projection is neither equal-area nor conformai, scale does not vary more than 0.06% throughout the quadrangle.

Cartographica: The International Journal for Geogr↗
USGS2014

Implications of Web Mercator and its Use in Online Mapping

Online interactive maps have become a popular means of communicating with spatial data. In most online mapping systems, Web Mercator has become the dominant projection. While the Mercator projection has a long history of discussion about its inappropriateness for general-purpose mapping, particularly at the global scale, and seems to have been virtually phased out for general-purpose global-scale print maps, it has seen a resurgence in popularity in Web Mercator form. This article theorizes on how Web Mercator came to be widely used for online maps and what this might mean in terms of data display, technical aspects of map generation and distribution, design, and cognition of spatial patterns. The authors emphasize details of where the projection excels and where it does not, as well as some of its advantages and disadvantages for cartographic communication, and conclude with some research directions that may help to develop better solutions to the problem of projections for general-purpose, multi-scale Web mapping.

Cartographica: The International Journal for Geogr↗
USGS1981

An examination of techniques for reformatting digital cartographic data. Part 2: The vector-to raster process.

Current graphic devices suitable for high-speed computer input and output of cartographic data are tending more and more to be raster-oriented, such as the rotating drum scanner and the color raster display. However, the majority of commonly used manipulative techniques in computer-assisted cartography and automated spatial data handling continue to require that the data be in vector format. The current article is the second part of a two-part paper that examines the state of the art in these conversion techniques. - from Author

Cartographica: The International Journal for Geogr↗
USGS1981

An examination of techniques for reformatting digital cartographic data/part 1: The raster-to- vector process.

Current graphic devices suitable for high-speed computer input and output of cartographic data are tending more and more to be raster-oriented, such as the rotating drum scanner and the color raster display. However, the majority of commonly used manipulative techniques in computer-assisted cartography and automated spatial data handling continue to require that the data be in vector format. This situation has recently precipitated the requirement for very fast techniques for converting digital cartographic data from raster to vector format for processing, and then back into raster format for plotting. The current article is part one of a two-part paper concerned with examining the state-of-the-art in these conversion techniques. In part one, algorithms to perform all phases of the raster-to-vector process are systematically outlined, and then compared in general terms. Examples of existing implementations of the raster-to-vector process are also described and evaluated. Part two will outline and compare algorithms to perform the reverse process, vector-to-raster conversion. Part two will also discuss raster-to-vector and vector-to-raster conversion as an integrated process.

Cartographica: The International Journal for Geogr↗
USGS1984

Applied cartographic communication: map symbolization for atlases.

A detailed investigation of the symbolization used on general-purpose atlas reference maps. It indicates how theories of cartographic communication can be put into practice. Two major points emerge. First, that a logical scheme can be constructed from existing cartographic research and applied to an analysis of the choice of symbolization on a map. Second, the same structure appears to allow the cartographer to specify symbolization as a part of map design. An introductory review of cartographic communication is followed by an analysis of selected maps' usage of point, area and line symbols, boundaries, text and colour usage.-after Author

Cartographica: The International Journal for Geogr↗