Cylindricalmathematically projected on a cylinder tangent to the equator. A projection showing accurate areas is called an equalarea map. A cylindrical projection is produced by wrapping a cylinder around a globe representing the earth. May 24, 2016 it discusses the general properties of map projections, aspects of mapping accuracy, and the different projection types. We will taker a closer look at the popular mercator projection and examine how the projection. The map projection is the image of the globe projected onto the cylindrical surface, which is then unwrapped into a flat surface. Because there is no limit to the number of possible map projections, there can be no comprehensive list. Map scale distortion of a secant cylindrical projection sf 1 along secant lines. Which landmasses appear much larger on the cylindrical projection than they actually are. Cylindrical projection definition at, a free online dictionary with pronunciation, synonyms and translation. This is a summary of map projections that have articles of their own on wikipedia or that are otherwise notable.
Every projection has its own set of advantages and disadvantages. A compromise aspectadaptive cylindrical projection for world maps je n n y, b. Map projections displaying the earth on 2 dimensional maps the world from space projection from esri, centered at 72 west and 23 south. Cylindrical projection wrap a sheet of paper around the globe in the form of a cylinder, transfer the geographic features of the globe on to it. A map derived from a secant projection surface has less overall distortion than a map from a tangent surface.
Variations of it appeared over the years by inventors who stretched the height of the lambert and compressed the width commensurately in various ratios. A map projection is a systematic transformation of the latitudes and longitudes of positions on the surface of the earth to a. The mercator projection, long popular but now less so, is a cylindrical projection of the latter type that can be constructed only mathematically. If the graticule of latitude and longitude are projected onto the cylinder and the cylinder unwrapped, then a gridlike pattern of straight lines of latitude and longitude would result. There are many different coordinate systems each one is better for certain purposes. Projections created from different surfaces would include cylindrical, conical, and azimuthal projections. This requires a systematic transformation of the latitudes and longitudes of locations from the surface of the globe into locations on a plane. A map projection is used to portray all or part of the. When we look at the projections, it is clear that countries with a large. The purpose of the map determines which projection should form the base for the map. A map projection s aspect is its orientation on the page or display screen.
Employment projections are the most frequentlyrequested kind of workforce statistic aside from the unemployment rate. A normal perspective projection onto a cylinder tangent at the equator. Map projections can be constructed to preserve at least one of these properties, though only in a limited way for most. Mercator projection is an example of cylindrical projection which became a standard map projection because of its ability to represent lines of steady course. A map is a projection of data usually from the real earth. But the term cylindrical as used in the field of map projections relaxes the last constraint entirely. Pseudocylindrical projection outlines tend to be barrelshaped rather than rectangular. Map projections explained a beginners guide youtube. Find out information about cylindrical map projection. Dec 10, 2016 a map projection describes how points on a plane, such as the pixels on your screen, correspond to points on the surface of the earth. This approximates the view of the earth from the sun on the winter solstice at noon in cambridge, ma. A projection that preserves the shape of features across the map is called conformal. Straight meridians and parallels that intersect at right angles.
In the normal, or equatorial aspect, all meridians and parallels are perpendicular straight lines. Meridians are geometrically projected onto the cylindrical surface, and parallels are mathematically projected. Although the earth is best represented by a spheroid, the earth is sometimes treated as a sphere. Cylindrical map projections are rectangles, but are called cylindrical because they can be rolled up and their edges mapped in a tube, or cylinder. The equal earth map projection became one of the journals most read papers, with more than 12,000 views. However, they do resemble cylindrical projections, with straight and parallel latitude lines, and can have equally spaced meridians, but meridians are curves, not straight lines. Pdf in this paper, we introduce some known map projections from a model of the. Map projection is the method of transferring the graticule of latitude and longitude on.
However, map projection refers specifically to a cartographic projection. Depending on the purpose of the map, some distortions are acceptable and others are not. Conic projection definition of conic projection by the. There is no limit to the number of possible map projections 1 projections are a subject of several pure mathematical fields, including differential geometry, projective geometry, and manifolds. Pseudocylindrical in standard presentation, these map the central meridian and parallels as straight lines. A map projection is a device for producing all or part of a sphere on a flat sheet. Type of projection cylindrical in standard presentation, these map regularlyspaced meridians to equally spaced vertical lines, and parallels to horizontal lines. Which landmasses on the cylindrical projection appear to be accurate in size. The lambert azimuthal equalarea projection is mathematically based on a plane tangent to the earth.
Pdf the equal earth map projection is a new equalarea pseudocylindrical projection for world maps. Family of cylindrical map projection nisa manzoor nasir mughal 2. 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. World maps in an atlas provide a spatial referencing system, but the same pieces of the earth can look different according to the map projection used for the map robinson et al, 1984.
Compare the size of landmasses on the cylindrical projection on the left with the robinson projection on the right to answer the following questions. Arno peters, a german historian and journalist, in 1973. A map projections aspect is its orientation on the page or display screen. This simple cylindrical projection converts the globe into a cartesian grid. Originally, this and other map projections were achieved by a systematic method of drawing the earths meridians and latitudes on the.
Although the earth is best represented by a spheroid, the earth is sometimes treated as a sphere to make mathematical calculations easier. Cylindrical map projection article about cylindrical map. In te rn a tio n a l jo u rn a l o f g e o g ra p h ica l. In cartography, a map projection is a way to flatten a globes surface into a plane in order to make a map. The mercator projection was used for its portrayal of direction. 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. What are the advantages and disadvantages of using a. The invention of the lambert cylindrical equalarea projection is attributed to the swiss mathematician johann heinrich lambert in 1772. D h maling, coordinate systems and map projections. A map projection produced by projecting the geographic meridians and parallels onto a cylinder which is tangent to the surface of a sphere, and then.
A cylindrical projection is any projection in which the meridians are mapped to parallel spaced vertical lines and latitudes are mapped to horizontal lines. Topic simple cylindrical map projection cylindrical equal area projection mercators projection cylindrical orthomorphic projection transverse mercators projection also called utm. It is the system of transformation of the spherical surface onto a plane surface. Map projections coach grigg ap human geography golf.
A map projection is the method to represent the spherical surface or object like that in two dimensional plane or flat surface. When projected on a planar map it produces an azimuthal or zenithal map projections. A systematic analysis of distortions in map projections notes for a course in map projections in the department of surveying engineering university of new brunswick introduction if we 1 ived on a flat earth there would be. Adaptive composite map projections geovisualization. Getting familiar with different types of map projections. We will focus rst on cylindrical projections but there are others. The name of the projection is the shape that the image is projected onto. Although certain perspective projections are important in astronomy, for example the orthographic. It is also known as the babinet projection, homalographic projection, homolographic projection, and elliptical projection. Feb 29, 2008 the three classes of map projections are cylindrical, conical and azimuthal. Maps were devised because they are much easier to use, store, and transport than globes, and they facilitated the development of much larger. Gauss conformal, lambert conic projection, albers equal area, cylindrical equal area, and more. Geometrical motivation conceptually, a cylindrical projection can be visualized by wrapping a cylinder around a globe and.
Map projections define the spatial relationship between locations on earth and their relative locations on a flat map are mathematical expressions which transform the spherical earth to a flat map cause the distortion of one or more map properties scale, distance. Scale increases perpendicular to the radii toward the periphery. 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. It is carried out by an orderly and systematic representation of the parallels of latitude and the meridians of longitude of the spherical earth or part of it on a plane surface on a conveniently chosen scale. Cylindrical projection a cylindrical projection is a type of map in which a cylinder is wrapped around a sphere the globe, and the details of the globe are projected onto the cylindrical surface. Learn what a map projection is, why they are used and what impact they have on maps gis systems. Without a coordinate system a map is just a drawing.
The zones are bounded by meridians 3 either side of a central meridian. Each projection preserves, compromises, or approximates basic metric properties in different ways. About map projectionthe classification of map projection. Each rectangular grid cell has the same size, shape, and area. 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. A projection that preserves the area of a feature across the map. In cartography, a map projection is a way to flatten a globes surface into a plane in order to. A compromise aspectadaptive cylindrical projection for. Equal earth map projection meets cartographic needs and. This kind of map projection has straight coordinate lines with horizontal parallels crossing meridians at right angles.
Pdf introducing the patterson cylindrical projection researchgate. David tenenbaum eeos 281 umb fall 2010 the graticule picture a light source projecting the shadows of the graticule. When the central axis of the developable surface is oriented eastwest, the projections aspect is. The earths surface projected on a map wrapped around the globe as a cylinder produces the cylindrical map projection. In 1569, gerardus mercator presented a cylindrical map projection that he devised for nautical navigation. Map projections massachusetts institute of technology. The projection maps lines of constant angular direction or compass bearing, known. Map projections a map projection is used to portray all or part of the round earth on a flat surface. Map projectionspdf versions of numerous projections. Comparison of the cylindrical equalarea projection and some cylindrical equalarea map projections with tissot indicatrix, standard parallels and aspect ratio history edit the invention of the lambert cylindrical equalarea projection is attributed to the swiss mathematician johann heinrich lambert in. Then, the cylinder is unwrapped into a flat surface, yielding a rectangularshaped map.
A paper describing the equal earth projection, written by patterson, jenny, and savric. Cylindrical map projections are one way of portraying the earth. Direction and shape are good at the equator to about latitude 40 44 n and s. Cylindrical projection definition is a projection as of a sphere or a spheroid on the surface of a cylinder. Mercator projection is an instance of a cylindrical projection which became a standard map projection due to its capacity to represent lines of steady course.
The only factor that distinguishes different cylindrical map projections from one another is the scale used when spacing the parallel lines on the map. Map projections continued projections can be based on axes parallel to the earths rotation axis equatorial, at 90 degrees to it transverse, or at any other angle oblique. Apr 25, 2017 the north to south stretching equals east to west but grows with latitude faster than east to west stretching in the case of central cylindrical projection. The study of map projections is the characterization of these distortions. A cylindrical projection can be imagined in its simplest form as a cylinder that has been wrapped around a globe at the equator.
Mercator projection an overview sciencedirect topics. However, the surface of projection may still be described as planar, cylindrical, or conic. Visualisation technical projections and coordinate systems. Lambert first described this equal area projection in 1772. All map projections distort the surface in some fashion. A compromise aspectadaptive cylindrical projection for world. The best known map projection is named for its inventor, gerardus mercator, who developed it in 1569. At places on map where the surface is outside the globe, features appear larger than in reality and scale factor is greater than 1. The reference source code is available in the java map projection library. Projected on a map formed into a cone gives a conical map projection. 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.
Some projections preserve distance or true direction, some maintain correct shapes, and others preserve the property of areal size. Cylindrical projection definition of cylindrical projection. Map projections are roughly classi ed into the types of surfaces that the globe is projected onto. The mercator projection is a cylindrical projection that was developed for navigation purposes. Map projections can be studied from the point of view of. The mercator projection was used for its portrayal of direction and shape, so it was helpful to the sailors of that time. It is the only projection that can accurately represent both areas and true direction from the center of the projection.
Jan 06, 2017 learn what a map projection is, why they are used and what impact they have on maps gis systems. Gnomonic azimuthal equidistant lambert azimuthal equal area albers equal area. Pdf the patterson cylindrical, a new projection designed for generalpurpose. The central parallel may be any line, but the traditional plate carree projection uses the equator. Like conic projections, cylindrical projections can also have tangent or secant cases. In this section, by an elementary method, we show the cylindrical method that mercator used to map. The mollweide projection is an equalarea, pseudo cylindrical map projection generally used for global maps of the world or night sky. This map projection is practical for nautical applications due to its ability to represent lines of constant course, known as rhumb lines, as straight segments that conserve the angles with the meridians.
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