Exercise in map projections university of texas at austin. A map projection is a systematic transformation of the latitudes and longitudes of locations from the surface of a sphere or an ellipsoid into locations on a plane. Mollweide in 1814 but not used until jacques babinet found it and reintroduced it as the homalographic in 1857. Mapthematics and geocart projections list isoperimetric. His major aim in developing this projection was to create a map on which the size of countries were accurately represented unlike on the mercator projection. What information do you want your readers to gain from it. In the socalled drake map, published about 1595, jodocus hondius shifted the central meridians 90 degrees so that europe, africa, and the americas could appear in one hemisphere, thereby showing the circumnavigational routes of francis drake. The werner projection places its standard parallel at the north pole. The study of map projections is the characterization of these distortions. It is possible to draw a map of the world on a moebius strip. Depending on the purpose of the map, some distortions are acceptable and others are not. The equal earth map projection depicts land masses and oceans at their true sizes relative to each other. Projection other than aitoff, gnomic, lamberts azimuthal equal area, orthographic, azimuthal equidistant, stereographic, general vertical nearsided, modified stereographic for alaska, chamberlin trimetric, polar stereographic, azimuthal, specific t.
It is the first printed world map based upon a doublecordiform polar projection, a form that would be much imitated by the likes of mercator in 1538 and salamanca and lafreri a decade or so later. Maps were devised because they are much easier to use, store, and transport than globes, and they facilitated the development of much larger. Polar cordiform projection, also terminated at the equator. This process is typically, but not necessarily, a mathematical procedure some methods are graphically based. World map on double cordiform projection world digital. This requires a systematic transformation of the latitudes and longitudes of locations from the surface of the globe into locations on a plane. Both the physical and political maps are in the public domain which means users can freely download and use them however they want to, including for commercial purposes. The central focus of this book is on the theory of map projections. Click ok in the two open windows and youll see the view transformed to appear in a robinson projection, which is a relatively new style of map projection for the earth designed to present the whole earth with a minimum of distortion at any location. Elements of map projection with applications to map and chart construction by deetz, charles henry, 1864. Untitled map of the world on a double cordiform projection, rome, antonio lafreri, c. Projection gis definition,meaning online encyclopedia. This map projection was breifly used by a number of cartographers who used it, gave it another name, and then stopped using it. Without a stated need, there is no unique or objective answer to this question.
Since the mass of the earth is not uniform at all points, and the direction of gravity changes, the shape of the geoid is irregular. All map projections necessarily distort the surface in some fashion. The figure of the earth and the reference surfaces used in surveying and mapping. Abraham ortelius and the hermetic meaning of the cordiform. 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. Map map a coordinate conversion from a geodetic coordinate system to a planar surface, converting geodetic latitude and longitude to plane map.
This is also the first map to apply the name america to the north american continent as well as to south america and to differentiate north and. A projection showing accurate areas is called an equalarea map. Map projections used in selected portolan style maps. Mathematical cartography also takes in map scales and their variation, the. Both the physical and political maps are in the public domain. Antiti map projections tn 6 a map is a representation of all or part of the earth drawn on a flat surface at a specific scale. Combining science, aesthetics, and technique, cartography builds on the premise that reality can be modeled in ways that communicate spatial information effectively the fundamental uses of traditional.
Apparently equivalent to a projection described by leszek. It is a bonne projection with one of the poles as its standard parallel. Angles, areas, directions, shapes, and distances can become distorted when transformed from a curved surface to a plane. Werner, theatrum orbis terrarum, cordiform projection, world map, fools head map, turkish map, family of love, hermeticism, jesuit symbolism, heart symbolism. A gnomonic map projection displays all great circles as straight lines, resulting in any straight line segment on a gnomonic map showing a geodesic, the shortest route between the segments two endpoints. The map must be drawn on both sides of the paper, inverting the image on one side. Columbuss view of a 750 league separation between ferro and asia was determined by the map he used. This world map on two sheets is an early work of the famous flemish cartographer gerardus mercator 151294. Its heart shape gives it the additional descriptor cordiform. It is the first printed world map based upon a double cordiform polar projection, a form that would be much imitated by the likes of mercator in 1538 and salamanca and lafreri a decade or so later. After decades of using only one map projection, the polyconic, for its mapping program, the u.
Every distinct map projection distorts in a distinct way. Since the mass of the earth is not uniform at all points, and the direction of gravity changes, the. The cordiform projection used by oronteus fineaus sic suggests the use of advanced mathematics. For example, if two roads cross each other at a 39 angle, then their images on a map with a conformal projection. Correct along all parallels and meridians in the default aspect. Jan 28, 2020 in cartography, a conformal map projection is one in which every angle between two curves that cross each other on earth is preserved in the image of the projection, i. All projections of a sphere on a plane necessarily distort the surface in some way and to some extent.
Arizona, new mexico, colorado and utah on a globe meet at 90. Since the earth is roughly the shape of an oblate spheroid, map projections are necessary for creating maps of the earth or parts of the earth that are represented on a plane such as a piece of paper or a computer screen. Projections transformation of curved earth to a flat map. If the scale of a map at any point is the same in any direction,the projection is conformal. Purchase coordinate systems and map projections 2nd edition. Map makers attempt to transfer the eartha round, spherical globeto flat paper. Because there is no limit to the number of possible map projections, there can be no comprehensive list. In cartography, a map projection is a way to flatten a globes surface into a plane in order to make a map. Scale is correct along all parallels and meridians. 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. One chooses a projection to meet an analytic or cartographic need. 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. For larger scale maps, including topographic quadrangles and the state base map series, conformal projections such as the transverse mercator and the.
The resulting double cordiform polar projection puts giss, and therefore nasa, to shame cp. World map on double cordiform projection world digital library. Pdf abraham ortelius and the hermetic meaning of the. Since any method of representing a spheres surface on a plane is a map projection, all map projections distort. The focus in this paper is on ortelius, for recent studies have suggested connections between ortelius, christopher plantin and a clandestine religious sect in antwerp, called the family of love family of charity, whose emblem was the heart, source of divine illumination. This is a summary of map projections that have articles of their own on wikipedia or that are otherwise notable. This is achieved by casting surface points of the sphere onto a tangent plane, each landing where a ray from the center of the sphere passes through the point on the surface and then on. Mollweide projection is an equalarea pseudocylindrical map projection that was developed by k. On the left is the werner and to the right is the bonne.
List of map projections wikimili, the best wikipedia reader. Map projection concerns the science of mathematical cartography, the techniques by which the earths dimensions, shape and features are translated in map form, be that twodimensional paper or two or three dimensional electronic representations. Arno peters, a german historian and journalist, in 1973. Arcview permits data to be viewed in various map projections but no new. The geoid is defined as the surface of the earths gravity field, which is approximately the same as mean sea level. The focus in this paper is on ortelius, for recent studies have suggested connections between ortelius, christopher plantin and a clandestine religious sect in antwerp, called the family of love family of charity, whose emblem was the heart, source of divine. It is perpendicular to the direction of gravity pull. Download the equal earth physical map for free geography. Map projection involves taking data whose spatial coordinates are defined in terms of latitude and longitude on a curved earth surface and transforming those data so that their spatial coordinates are defined in terms of easting and northing or x,y on a flat map surface. Further, the shape given to the antarctic continent suggests the possibility, if not the probability, that the original source maps were compiled on a stereographic or gnomic type of projection involving the. Download the equal earth physical map for free geography realm. Whether you treat the earth as a sphereor a spheroid, you must transform its threedimensional surface to create a flat map sheet. The cordiform projection employed by oronce fine, gerard mercator and abraham ortelius may have had a hermetic meaning.
Under projections of the world youll see a projection type labeled robinson. The resulting map, when one uses the lambert cylindrical projection, with the poles at the edges of the strip, has the curious property that a pin pushed through the map exits at the antipodal point. The appearance, classification and naming of map projections. One easy way to understand how map projections alter spatial properties is to visualize shining a light through the earth onto a surface, called the projection surface. 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. The equalarea werner projection is shaped like a heart, or cordiform french mapmaker oronce fine used this projection separately for northern and southern hemispheres in 1531, creating a double cordiform as seen above. A map projection is any method of representing the surface of a sphere or other threedimensional body on a plane. Map projections are the different techniques used by cartographers for presenting a round globe on a flat surface.
Geological survey usgs now uses several of the more common projections for its published maps. The focus in this paper is on ortelius, for recent studies have suggested. Dec 27, 2002 a map projection is one of many methods used to represent the 3dimensional surface of the earth or other round body on a 2dimensional plane in cartography mapmaking. The map is not only a visual delight but is also noteworthy for its cartographic content. All map projections distort the surface in some fashion. This was an equalarea, heartshaped world map projection generally called a cordiform projection which was used in the 16th and 17th centuries. Is wgs84 fine since its a relatively small area, or should i use some other kind of projection. A map projection is a geometric function that transforms the earths curved, ellipsoidal surface onto a flat, 2dimensional plane. Although the projection procedure inevitably introduces systematic spatial distortions, particular types of distortion can be minimized to suit the geographic scope and intended use of the map data. World map on double cordiform projection viewer world. This booklet provides a conceptual introduction to.
1627 1602 696 844 1581 578 1303 155 1289 482 393 849 806 1465 1245 760 1433 1586 189 294 1202 1059 1438 410 380 1074 1647 1586 1440 810 387 1244 1194 1088 1014 57 613 894 121 1113 259