Mapthematics and geocart projections list transverse. Eckert iv projection matlab mathworks united kingdom. The eckert iv map projection properties of maps when considering what map to use for a particular purpose, you need to know what type of properties the map has. Equal earth map projection meets cartographic needs and. The equal earth projection blends characteristics of the eckert iv and putnins. After decades of using only one map projection, the polyconic, for its mapping program, the u. This equal area projection is used primarily for world maps. The length of polar line is half that of the equator, and lines of longitude are sinusoids. A computational method for the hufnagel pseudocylindric. Peters projection map, widely used in educational and. The curved sides and varying distance between lines of latitude help reduce the scale and area distortion at high latitudes. Many smallscale map projections exist, and they have different shapes and distortion characteristics.
Supported linear units, map projections, and projected. The lateral meridians are semicircles, which give the projection a rounded shape and smooth corners where the lateral meridians meet the pole lines. Combo with map projections and 5 others flashcards quizlet. A map projection that fairly accurately shows shape and direction, but distorts distance and size of land masses. A map projection is any of many methods used in cartography mapmaking to represent the twodimensional curved surface of the earth or other body on a plane. The term projection here refers to any function defined on the earths surface and with values on the plane, and not necessarily a geometric projection. While the peters projection map is superior in its portrayal of proportions and sizes, its importance goes far beyond questions of cartographic accuracy. Map projections there are many types of projections. Eckert greifendorff eckert i eckert ii eckert iii eckert iv eckert v eckert vi mollweide natural earth natural earth ii new zealand map grid ney modified conic orthographic patterson plate carree polyconic quartic authalic rectified skew orthomorphic robinson sinusoidal stereographic times transverse cylindrical equalarea transverse mercator. Commonly, a map projection is a systematic transformation of the latitudes and longitudes of locations on the surface of a sphere or an ellipsoid into locations on a plane. Eckert iv projection gis wiki the gis encyclopedia. Although the earth is best represented by a spheroid, the earth is sometimes treated as a sphere to make mathematical calculations easier.
Eckert iv projection is a pseudocylindrical map projection. Eckert iii projection gis wiki the gis encyclopedia. Since the shape of this projection occupies more space than an ellipse, as well as a sinusoid, the stretching of continents at the equator is considerably more. The paired comparison test of nine commonly used map projections reveals that the mapreaders in. The eckert iii projection is flatpolar world map projection developed by max eckert, a german professor, and published in 1906 as one of 6 world map projections. Pdf a guide to selecting map projections for world and. The eckert iv projection is another attempt to moderate the behavior of the equalarea sinusoidal projection. Eckert iv is an equal area projection used primarily for world maps. Eckert iv is an equalarea projection with very low. A guide to selecting map projections for world and hemisphere maps.
This projection is pseudocylindrical and equalarea. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Depending on the purpose of the map, some distortions are acceptable and others are not. This pseudocylindrical projection is used primarily for world maps. You can turn the layers on or off, customise the lines, fills and editable font text, add your own information to create your own styles. Eckert ivhelp arcgis for desktop arcgis desktop arcgis online. This means that the latitude lines are parallel and straight, while most meridians are curved. The length of polar line is half that of the equator, and lines of longitude are semiellipses, or portions of ellipses. Vector world political map in the eckert iv projection uk. Fully editable and layered in illustrator cs and pdf vector formats. Topographic mapping ellipsoidal form of british isles before the 1920s.
The length of the polar lines is half that of the equator, and lines of longitude are. Eckert ii is a pseudo cylindrical equalarea projection. The subsections below describe the eckert iv projection properties. Fully editable and layered in illustrator and pdf vector formats. More precisely, a map projection requires a transformation. This projection is commonly used for thematic and other world maps requiring accurate areas. This design is sometimes mistaken for the projection of orteliuss oval map, which lacks constant scale along parallels and thus is not pseudocylindrical. In addition, the eckert iv projection, which we use as the second. Issues each type of map projection has problemsand the biggest problem is trying to fit a round globe onto a flat. Pdf the equal earth map projection is a new equalarea pseudocylindrical projection for world maps. The length of the polar lines is half that of the equator, and lines of longitude are semiellipses, or portions of ellipses. Actual size of the projection minus the black or white background. In the equatorial aspect where the equator is shown as the horizontal axis the network of longitude and latitude lines consists solely of straight lines, and the outer boundary has the distinctive shape of an elongated hex. Eckert ii at mapthematics cartographic projection procedures pdf by gerald i.
Map of the world in eckert iv projection ordnance survey. Can be compressed northsouth to provide a transverse equirectangular projection, but rarely done. It was first described by max eckert in 1906 as one of a series of three pairs of pseudocylindrical projections. Strebed acollege of earth, ocean, and atmospheric sciences, oregon state university, corvallis, or, usa. The team decided that a new projection was needed that would have some of the characteristics of these projections. There are many properties that might be relevant to all sorts of questions but there are two major properties that we will consider here. Eckert iv projection is confirmed by monmonier 2004. Max eckertgreifendorff list of map projections eckert iv projection eckert vi projection.
It is free of distortion only at the two points where the 40. Supported linear units, map projections, and projected coordinate systems map projection parameters name sphereonly parameters key below aitoff yes lam0 albers equal area conic lam0 phi1 phi2 phi0 azimuthal equidistant. Eckert iv projection, with tissot indicatrices, 30 graticule. The peters map, the work of the german historian arno peters, provides a helpful corrective to the distortions of traditional maps. The eckert vi projection is an equalarea pseudocylindrical map projection. All projections of a sphere on a plane necessarily distort the surface in some way and to some extent. Cartographers often choose map projections by determining the types of distortion they want to minimize or eliminate. Although the earth is best represented by a spheroid, the earth is sometimes treated as a sphere. Eckert iv and wagner iv came closest to meeting the teams design preferences but still had aesthetic issues. The following table lists a representative sample of the map projections supported by the ibm informix spatial data types. In each pair, the meridians have the same shape, and the oddnumbered projection has equally spaced parallels. Centred on the greenwich meridian the eckert iv projection offers an alternative to a rectangular outline for world maps. In cartography, a map projection is a way to flatten a globes surface into a plane in order to make a map.
For larger scale maps, including topographic quadrangles and the state base map series, conformal projections such as the transverse mercator and the lambert conformal conic are used. Modified polyconic, international map of the world series 111. This is the os wall map of the world in an eckert iv projection. They can also determine which of the three projection types cylindrical, conic, or azimuthal best suits their purpose and region of interest. The eckert iv projection is an equalarea pseudocylindrical map projection. A computational method for the hufnagel pseudocylindric map projection family bernhard jennya,b, bojan savrica,c and daniel r. The eckert ii projection is an equalarea pseudocylindrical map projection. User preferences for world map projections cartography and. Geological survey usgs now uses several of the more common projections for its published maps. The beginning of the book contains substantial introductory information about map projection families and distortions. Eckert iv is an equalarea pseudocylindrical map projection for world maps. Vector world political map in the eckert iv projection us.
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