location, location, location.  two measurements define location on globe measured in degrees from...

Download Location, Location, Location.  Two measurements define location on globe Measured in degrees from a starting point  Latitude Distance north or south

Post on 29-Dec-2015




1 download

Embed Size (px)


  • Location, Location, Location

  • Two measurements define location on globeMeasured in degrees from a starting pointLatitudeDistance north or south of equatorNorth also designated as positiveLongitudeDistance east or west of a starting meridianMeridian: line running from pole to polePrime meridian: through Greenwich, EnglandLink

  • Starting point: Equator!Angular distance from equator measures latitude

  • Starting point: Prime meridianAngular distance east or west of prime meridian

  • Globe is a model of Earth, showing locations of land and waterGreat circle:Map is a flat representation of part of Earths surfaceChart is a flat representation of ocean or air Both maps and charts have distortion

  • Projections are ways of transferring Earth structures/locations onto a flat mapDifferent projections are used for different purposesProjections always create some sort of distortion

  • Medieval European T-O Map. In medieval Europe one of the most common forms of rendering the earth was the mappae mundi of which more than a thousand have survived. The T-O map is one kind of mappae mundi. The T-O image reproduced here comes from the encyclopedia of knowledge produced by Isidore, Bishop of Seville, in 630 A.D., and was printed in Augsburg in 1472.

  • The greatest "inventor" of sixteenth century Europe was map maker Gerhardus Mercator whose 1569 summary map, publicized by the learned Richard Hakluyt in his Principal Navigations, Voyages and Discoveries of the English Nation (London: 1589), liberated cartography from dependence on Ptolemy, and included a projection that allowed navigators to understand the coasts of the New World. These maps silently promoted a Eurocentric view that privileged the Western image. Generations of European and American students have been indoctrinated with the glories of nationalism and colonialism through this map.

  • no matter how the earth is divided up, it can not be unrolled or unfolded to lie flat (undevelopable shape).PROJECTIONS

  • (a) Azimuthal (gnomonic) (b) Cylindrical (c) Conic

  • Views of projected surfaces

  • ConicalGlobe sits under a cone, touching along pre-selected line of latitudeProjection developed by cutting cone lengthwise and unrollingDistortion greatest at latitudes distant from where cone touchesPROJECTION CLASSIFICATION

  • ConicalPolyconic envelopes globe with an infinite number of cones, each with its own standard parallelPROJECTION CLASSIFICATION

  • Cylindricalprojected onto a cylinder which is also cut lengthwise and unrolledPROJECTION CLASSIFICATION

  • Cylindrical Distortionprojection of the entire world, significant distortion occurs at the higher latitudesPROJECTION CLASSIFICATION

  • Cylindrical Distortionsizes of Greenland vs. AfricaPROJECTION CLASSIFICATION

  • Planar/Azimuthalportion of earths surface is transformed from a perspective point to a flat surfacePROJECTION CLASSIFICATION

  • Mercatorcylindrical, conformal projectionangular relationships are preservedparallels and meridians appear as straight linesparallels are farther apart with increased distance from equatorCOMMON PROJECTIONS

  • Polar Stereographicdirections are true from center point conformal projection: over a small area, angles in the map are the same as the corresponding angles on Earth's surfacemeridians are straight and radiating; parallels are concentric circlesshows only one hemisphereCOMMON PROJECTIONS

  • Robinsondeveloped to minimize appearance of angular and area distortiondistorts shape, area, scale and distance in an attempt to balance errors of projection propertiesCOMMON PROJECTIONS

  • size of an object on a map compared to the actual object on the groundmay not be the same in all directions from a point depending on projection used

  • SCALE TYPESVerbal scaledescribes the scale in wordsi.e. one centimeter represents one kilometercommonly found on popular atlases and maps

  • Visual scale (bar scale or graphic scale)graphically illustrates relationship between map distance and ground distance.most commonremains correct if reduced or enlargedSCALE TYPES

  • Visual scale (bar scale or graphic scale)SCALE TYPES

  • Representative Fraction (RF)ratio (proportion) between map distance to earth distancei.e. 1:50,000most versatile; not tied to any specific unitsSCALE TYPES

  • large scale: show a small area with a large amount of detail.small scale: show a large area with a small amount of detailall relativeLARGE VS SMALL SCALE



View more >