Tissot’s indicatrix, a geometric equation used to show distortion on maps, explains the problems with Mercator. The Mercator, however, makes the North look much larger. Therefore, Peters argued, the Mercator projection
Mercator projection
The Mercator projection is a cylindrical map projection presented by the Flemish geographer and cartographer Gerardus Mercator in 1569. It became the standard map projection for nautical purposes because of its ability to represent lines of constant course, known as rhumb lines or loxo…
Why do people criticize the Mercator map?
The most obvious criticism is that it distorts the size of countries near the poles. The classic example is Greenland vs Africa. On a Mercator projection, they look about the same size. In reality Africa is *way* bigger than Greenland.
Why would you use a Mercator projection?
This projection is widely used for navigation charts, because any straight line on a Mercator projection map is a line of constant true bearing that enables a navigator to plot a straight-line course.
What is an issue the Mercator and Peters projection both share?
Unfortunately, geographers and cartographers agree that neither map projection is appropriate—the Mercator vs. Peters controversy is, therefore, a moot point. Both maps are rectangular projections that are poor representations of a spherical planet.
What is the difference between a Mercator map and Peters projection?
In addition, Mercator only distorts longitudinal distances (except very close to the poles), whereas Peters screws up the scale almost everywhere for both longitude and latitude. This is why Mercator beats out Peters in the world of cartography, and why Google Maps uses a modified Mercator projection.
What is a Mercator projection and why is it misleading?
Mercator maps distort the shape and relative size of continents, particularly near the poles. This is why Greenland appears to be similar in size to all of South America on Mercator maps, when in fact South America is more than eight times larger than Greenland.
What is one positive thing about the Mercator projection?
Advantage: The Mercator map projection shows the correct shapes of the continents and directions accurately. Disadvantage: The Mercator map projection does not show true distances or sizes of continents, especially near the north and south poles.
What is the main problem with the Mercator projection map?
Because the linear scale of a Mercator map increases with latitude, it distorts the size of geographical objects far from the equator and conveys a distorted perception of the overall geometry of the planet.
What is one disadvantage of the Peters Projection?
Disadvantages: Peters's chosen projection suffers extreme distortion in the polar regions, as any cylindrical projection must, and its distortion along the equator is considerable.
How does Mercator projection fail?
Although the linear scale is equal in all directions around any point, thus preserving the angles and the shapes of small objects, the Mercator projection distorts the size of objects as the latitude increases from the equator to the poles, where the scale becomes infinite.
Why don't we use the Peters Projection Map?
The Gall-Peters map shows the correct sizes of countries, but it also distorts them. Countries are stretched horizontally near the poles and vertically near the Equator, so although the size may be right, the shape definitely isn't.
Why does Google maps use the Mercator projection?
A Google employee explained in 2009 that the company used a Mercator map because it helped preserve angles of roads: “The first launch of Maps actually did not use Mercator, and streets in high latitude places like Stockholm did not meet at right angles on the map the way they do in reality.”
What are some common problems with different map projections?
Because you can't display 3D surfaces perfectly in two dimensions, distortions always occur. For example, map projections distort distance, direction, scale, and area.
What do the Gall-Peters and Mercator projections show?
The idea is that in the Mercator map, Europe is seen as a much larger land mass and appears reasonably large compared to the Gall-Peters projection, which shows Europe as a much smaller mass, almost insignificant, when compared to regions like Africa.
Who created the Mercator projection?
The most popular version is the Mercator projection, created by Flemish cartographer Gerardus Mercator in 1569. It's been widely used for centuries, including today in various forms by Google Maps and many other online services. This map preserves directional bearing, presenting rhumbs (imaginary lines that cut all meridians at the same angle) ...
Which projection has the same flaws as the Mercator projection?
The Gall-Peters projection. Despite these benefits, the Gall-Peters projection has its flaws. It doesn't enlarge areas as much as the Mercator projection, but certain places appear stretched, horizontally near the poles and vertically near the Equator.
What episode of The West Wing is the Gall-Peters?
You may remember this map from season two, episode 16 of "The West Wing," when a group of cartographers visit the White House to ask that the president "aggressively support" requiring every school in America to teach geography using the Gall-Peters instead of the Mercator.
Who invented the mercator?
Wikimedia Commons. One of the best alternatives to the Mercator projection was presented in 1974 at a conference in Germany by Dr. Arno Peters, who claimed he invented it — though well after the discovery of an identical map made by James Gall in the 1800s.
Is Mercator projection misleading?
But to most people, the Mercator projection is highly misleading. Tissot's indicatrix, a geometric equation used to show distortion on maps, explains the problems with Mercator.
What is the Mercator projection?
The Mercator projection is a cylindrical map projection presented by the Flemish geographer and cartographer Gerardus Mercator in 1569 . It became the standard map projection for nautical purposes because of its ability to represent lines of constant course, known as rhumb lines or loxodromes, as straight segments that conserve the angles with the meridians. Although the linear scale is equal in all directions around any point, thus preserving the angles and the shapes of small objects (which makes the projection conformal ), 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.
What is the Gall Peters projection?
The Gall–Peters projection, named after James Gall and Arno Peters, is one specialization of a configurable equal-area map projection known as the equal-area cylindric or cylindrical equal-area projection. It achieved considerable notoriety in the late 20th century as the centerpiece of a controversy about the political implications of map design.
Who promotes maps based on projections?
Maps based on the projection are promoted by UNESCO, and they are also widely used by British schools.
How is the Mercator projection determined?
The Mercator projection is determined by the requirement that the projection be conformal. One implication of this is the "isotropy of scale factors", which means that the point scale factor is independent of direction, so that small shapes are preserved by the projection. This implies that the vertical scale factor, h, equals the horizontal scale factor, k. Since k = sec φ, so must h .
Who developed the Mercator projection?
Joseph Needham, a historian of China, wrote that the Chinese developed the Mercator projection hundreds of years before Mercator did, using it in star charts during the Song Dynasty. However, this was a simple, and common, case of misidentification. The projection in use was the equirectangular projection .
What is a mercator projection?
The Mercator projection maps all lines with constant bearing ( rhumbs (mathematically known as loxodromes—those making constant angles with the meridians) to straight lines. The two properties, conformality and straight rhumb lines, make this projection uniquely suited to marine navigation: courses and bearings are measured using wind roses or protractors, and the corresponding directions are easily transferred from point to point, on the map, with the help of a parallel ruler (for example).
Why did Mercator use sinusoidal projection?
Because of great land area distortions, some consider the projection unsuitable for general world maps. Therefore, Mercator himself used the equal-area sinusoidal projection to show relative areas. However, despite such distortions, the Mercator projection was, especially in the late 19th and early 20th centuries, perhaps the most common projection used in world maps, despite being much criticized for this use.
Why is the Mercator projection used in navigation?
It became the standard map projection for navigation because it is unique in representing north as up and south as down everywhere while preserving local directions and shapes. The map is thereby conformal. As a side effect, the Mercator projection inflates the size of objects away from the equator.
Which projection exaggerates areas far from the equator?
The Mercator projection exaggerates areas far from the equator .
Why is a marine chart based on a mercator?
Practically every marine chart in print is based on the Mercator projection due to its uniquely favorable properties for navigation . It is also commonly used by street map services hosted on the Internet, due to its uniquely favorable properties for local-area maps computed on demand. Mercator projections were also important in the mathematical development of plate tectonics in the 1960s.
