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Map making Yinduo Ma (Mandy). ??? We can make a cylinder on the flat.

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Presentation on theme: "Map making Yinduo Ma (Mandy). ??? We can make a cylinder on the flat."— Presentation transcript:

1 Map making Yinduo Ma (Mandy)

2 ??? We can make a cylinder on the flat.

3 History  Ancient Chinese map  200 B.C The Greeks understood that the earth was a sphere.  150 A.D Ptolemy proposed a system of projections and coordinate systems that are still used today.  16 century Mercator created a map- the Mercator Projection  20 century Aerial photographs, computers, electronic distance-measuring instruments, inertial navigation systems, remote sensing, and applications of space science create new extensions of cartography's reach.

4 Mathematics Topics Scale Coordinate Systems Projection

5 Mercator Projection cylindrical map projection It became the standard map projection for nautical purposes. the linear scale is equal in all directions around any point, thus preserving the angles and the shapes of small objects.

6 Mercator Projection

7 For small elements, the angle PKQ is approximately a right angle and therefore The previously mentioned scaling factors from globe to cylinder are given by parallel scale factor meridian scale factor Since the meridians are mapped to lines of constant x we must have x=R(λ−λ 0 ) and δx=Rδλ, (λ in radians). Therefore in the limit of infinitesimally small elements

8 Mercator Projection Formula

9 Mercator Projection the Mercator projection distorts the size and shape of large objects, as the scale increases from the Equator to the poles, where it becomes infinite. Greenland takes as much space on the map as Africa, when in reality Africa's area is 14 times greater and Greenland's is comparable to Algeria's alone

10 Gall–Peters projection specialization of a configurable equal-area map projection known as the equal-area cylindric or cylindrical equal-area projection. Maps based on the projection are promoted by UNESCO, and they are also widely used by British schools.

11 Gall–Peters projection

12 Formula

13 Gall–Peters projection Popular culture American show – The West Wing Military strategist – Thomas Barnett

14 Winkel tripel projection a modified azimuthal map projection. arithmetic means of the equirectangular projection and the Aitoff projection. minimizing three kinds of distortion: area, direction and distance

15 Winkel tripel projection whereλ is the longitude minus that of the central meridian of the projection, φ is the latitude, φ is the standard parallel for the equirectangular projection, and α is the unnormalized cardinal sine function (with the discontinuity removed). In his proposal, Winkel set : A closed-form inverse mapping does not exist, and computing the inverse numerically is somewhat complicated.

16 Winkel tripel projection

17 Winkel tripel fares well against several other projections analyzed against their measures of distortion, producing small distance errors, small combinations of Tissot indicatrix ellipticity and area errors, and the smallest skewness of any of the projections they studied.

18 Winkel tripel projection Winkel tripel projection as the standard projection for world maps made by the National Geographic Society.

19 Projection Azimuthals and related Conics Cylindricals Pseudoconics Pseudocylindricals

20 Azimuthals and related

21 Conics

22 Cylindricals

23 Pseudoconics

24 Pseudocylindricals

25 Question Gall–Peters projection and Mercator Projection belong to what kind of projection. Answer – Cylindrical


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