Cartography

Question 1

Equirectangular is also known as?

Answer 1

Equidistant cylindrical

or rectangular

Question 2

What type of map is an equirectangular?

Answer 2

Cylindrical

Question 3

Who invented the equirectangular projection? When?

Answer 3

Marinus of Tyre, CE 100 (some say 120)

Question 4

What is a conformal map projection?

Answer 4

A projection in which any angle on Earth

is preserved in the image of the projection.

Question 5

Describe the equirectangular projection

Answer 5

The projection maps meridians to vertical straight lines of constant spacing (for meridional intervals of constant spacing), and circles of latitude to horizontal straight lines of constant spacing (for constant intervals of parallels).

Question 6

What does it mean to say a projection is equidistant?

Answer 6

The projection maintains scale along one or more lines, or from one or two points to all other points on the map.

Question 7

Describe how the equirectangular projection’s condition is equidistant.

Answer 7

It is equidistant along all lines of latitude and longitude.

Question 8

What is Tissot’s indicatrix

Answer 8

(Tissot indicatrix, Tissot’s ellipse, Tissot ellipse, ellipse of distortion)

A mathematical contrivance presented by French mathematician Nicolas Auguste Tissot in 1859 and 1871 in order to characterize local distortions due to map projection.

Question 9

Who invented the Cassini (Cassini-Soldner or simply Soldner) projection, and when?

Answer 9

Described by César-François Cassini de Thury in 1745.

Question 10

Describe the Cassini projection

Answer 10

It is the transverse aspect of the equirectangular projection, in that the globe is first rotated so the central meridian becomes the “equator”, and then the normal equirectangular projection is applied.

Question 11

Describe Cassini distortions

Answer 11

Areas along the central meridian, and at right angles to it, are not distorted. Elsewhere, the distortion is largely in a north-south direction, and varies by the square of the distance from the central meridian. As such, the greater the longitudinal extent of the area, the worse the distortion becomes.

Question 12

What type of projection is the Cassini?

Answer 12

Cylindrical

Question 13

Describe the equidistant nature of the Cassini projection.

Answer 13

Distances along central meridian are conserved.

Distances perpendicular to central meridian are preserved.

Question 14

Who invented the Mercator projection, and when?

Answer 14

Flemish geographer and cartographer Gerardus Mercator in 1569.

Question 15

What is a line of constant course?

Answer 15

Known as rhumb lines or loxodromes, these are straight segments that conserve the angles with the meridians.

Question 16

Is the Mercator projection cylindrical?

Answer 16

Yes

Question 17

Is the Mercator map projection conformal?

Answer 17

Yes: The linear scale is equal in all directions around any point, thus preserving the angles and the shapes of small objects.

Question 18

Describe Mercator map distortion.

Answer 18

The Mercator projection distorts the size of objects as the latitude increases from the Equator to the poles, where the scale becomes infinite. So, for example, landmasses such as Greenland and Antarctica appear much larger than they actually are relative to land masses near the equator, such as Central Africa.

Question 19

Who made the Web Mercator and when?

Answer 19

A variant of the Mercator projection and the de facto standard for Web mapping applications. It rose to prominence when Google Maps adopted it in 2005.

Question 20

How is a Web Mercator different from a Mercator map projection? What distortion does this cause?

Answer 20

Web Mercator uses the spherical formulas of the Mercator projection at all scales whereas large-scale Mercator maps normally use the ellipsoidal form of the projection. The discrepancy is imperceptible at the global scale but causes maps of local areas to deviate slightly from true ellipsoidal Mercator maps at the same scale. This deviation becomes more pronounced further from the equator, and can reach as much as 35 km on the ground.

Question 21

Is the Web Mercator projection conformal?

Answer 21

The Web Mercator is not quite conformal due to its use of ellipsoidal datum geographical coordinates against a spherical projection. Rhumb lines are not straight lines.

Question 22

Why do Google and other online map services use Web Mercator?

Answer 22

The benefit of the Web Mercator is that the spherical form is much simpler to calculate, saving many computing cycles.

Question 23

Who made the Transverse Mercator map projection, and when?

Answer 23

The ellipsoidal form of the transverse Mercator projection was developed by Carl Friedrich Gauss in 1825 and further analysed by Johann Heinrich Louis Krüger in 1912.

Question 24

Also known as Gauss–Krüger, Gauss conformal

Answer 24

Transverse Mercator

Question 25

Who invented the sinusoidal projection and when?

Answer 25

Jean Cossin of Dieppe was one of the first mapmakers to use the sinusoidal, appearing in a world map of 1570

Question 26

The sinusoidal projection is a _________ projection.

Answer 26

pseudocylindrical equal-area map

Question 27

The sinusoidal projection is also known as _________

Answer 27

Sanson–Flamsteed or the Mercator equal-area projection

Question 28

Describe the Sinusoidal projection’s Equal-area, Equidistant nature and how this creates the map’s shape.

Answer 28

Scale is constant along the central meridian, and east–west scale is constant throughout the map. Therefore, the length of each parallel on the map is proportional to the cosine of the latitude, as it is on the globe. This makes the left and right bounding meridians of the map into half of a sine wave, each mirroring the other. Each meridian is half of a sine wave with only the amplitude differing, giving the projection its name. Each is shown on the map as longer than the central meridian, whereas on the globe all are the same length.

Question 29

Who invented the Mollweide Projection, and when?

Answer 29

The projection was first published by mathematician and astronomer Karl Brandan Mollweide of Leipzig in 1805. It was reinvented and popularized in 1857 by Jacques Babinet, who gave it the name homalographic projection.

Question 30

What type of projection is the Mollweide projection?

Answer 30

equal-area, pseudocylindrical

The projection trades accuracy of angle and shape for accuracy of proportions in area, and as such is used where that property is needed, such as maps depicting global distributions.

Question 31

What are the properties of a Mollweide projection?

Answer 31

The equator is represented as a straight horizontal line perpendicular to a central meridian one-half its length. The other parallels compress near the poles, while the other meridians are equally spaced at the equator.

The meridians at 90 degrees east and west form a perfect circle, and the whole earth is depicted in a proportional 2:1 ellipse.

Question 32

Describe the type of map that the Goode homolosine projection is.

Answer 32

The Goode homolosine projection (or interrupted Goode homolosine projection) is a pseudocylindrical, equal-area, composite map projection used for world maps

Question 33

Who invented the Goode homosine projection, and when?

Answer 33

The projection was developed in 1923 by John Paul Goode as an evolution to his 1916 experiments in interrupting the Mollweide projection.

Question 34

Who invented the American Polyconic projection, and when?

Answer 34

The American polyconic projection was probably invented by Ferdinand Rudolph Hassler around 1825.

Question 35

What class of projections does the American Polyconic projection belong to?

Answer 35

Polyconic projection class

Question 36

Who invented the Bottomley projection, why’d they do it, and when did they do it?

Answer 36

It was introduced by Henry Bottomley as an alternative to the Bonne projection to reduce the extent of extreme distortion at the edges and give a more satisfying overall shape. 2003

Question 37

Who invented the Bonne Projection, and when?

Answer 37

Although named after Rigobert Bonne, the projection was in use prior to his birth, in 1511 by Sylvano, Honter in 1561, De l’Isle before 1700 and Coronelli in 1696. Both Sylvano and Honter’s usages were approximate, however, and it is not clear they intended to be the same projection.

Question 38

What type of projection is the Bonne Projection?

Answer 38

The Bonne projection is a pseudoconical equal-area map projection

Question 39

Describe Bonne distortion

Answer 39

Parallels of latitude are concentric circular arcs, and the scale is true along these arcs. On the central meridian and the standard latitude shapes are not distorted.

Question 40

Who invented the Werner projection, and when?

Answer 40

It is sometimes called Stab-Werner in reference to two originators: Johannes Werner, a parish priest in Nuremberg, refined and promoted this projection that had been developed earlier by Johannes Stabius of Vienna around 1500.

Question 41

How is the Werner projection related to the Bonne projection?

Answer 41

The Werner projection is a limiting form of the Bonne projection, having its standard parallel at one of the poles (90°N/S). Distances along each parallel and along the central meridian are correct, as are all distances from the north pole.

Question 42

Who invented the Albers projection, and when?

Answer 42

Heinrich C. Albers, 1805

Question 43

Describe the Albers projection’s distortion

Answer 43

Although scale and shape are not preserved, distortion is minimal between the standard parallels.