As in all cylindrical projectionsparallels and meridians are straight and perpendicular to each other.
They share the same underlying mathematical construction and consequently the transverse Mercator inherits many traits from the normal Mercator: Both projections are cylindrical: For the transverse Mercator, the axis of the cylinder lies in the equatorial plane, and the line of tangency is any chosen meridian, thereby designated the central meridian.
Both projections may be modified to secant forms, which means Mercator projection definition scale has been reduced so that the cylinder slices through the model globe. Both exist in spherical and ellipsoidal versions.
Both projections are conformalso that the point scale is independent of direction and local shapes are well preserved; Both projections have constant scale on the line of tangency the equator for the normal Mercator and the central meridian for the transverse.
Since the central meridian of the transverse Mercator can be chosen at will, it may be used to construct highly accurate maps of narrow width anywhere on the globe. The secant, ellipsoidal form of the transverse Mercator is the most widely applied of all projections for accurate large-scale maps.
Spherical transverse Mercator[ edit ] In constructing a map on any projection, a sphere is normally chosen to model the Earth when the extent of the mapped region exceeds a few hundred kilometers in length in both dimensions. For maps of smaller regions, an ellipsoidal model must be chosen if greater accuracy is required; see next section.
The spherical form of the transverse Mercator projection was one of the seven new projections presented, inby Johann Heinrich Lambert.
Freebase ( / 0 votes) Rate this definition. Mercator projection. The Mercator projection is a cylindrical map projection presented by the Flemish geographer and cartographer Gerardus Mercator in Mercator definition is - of, relating to, or drawn on the Mercator projection. of, relating to, or drawn on the Mercator projection See the full definition. SINCE Menu. JOIN MWU Gain access to thousands of additional definitions and advanced search features—ad free! JOIN NOW. The Mercator projection is a cylindrical map projection presented by the Flemish geographer and cartographer Gerardus Mercator in It became the standard map projection for nautical navigation because of its ability .
All other meridians project to complicated curves. The poles lie at infinity. The points on the equator at ninety degrees from the central meridian are projected to infinity. The shapes of small elements are well preserved. The projection is not suited for world maps.
Distortion is small near the equator and the projection particularly in its ellipsoidal form is suitable for accurate mapping of equatorial regions. Distortion is small near the central meridian and the projection particularly in its ellipsoidal form is suitable for accurate mapping of narrow regions.
On the sphere it depends on latitude only. The scale is true on the equator. It is a function of x on the projection. On the sphere it depends on both latitude and longitude.
The scale is true on the central meridian. The two lines are not meridians. Grid north and true north coincide. It increases as the poles are approached.
Grid north and true north do not coincide. The projection is conformal with a constant scale on the central meridian. This was proved to be untrue by British cartographer E.
Thompson, whose unpublished exact closed form version of the projection, reported by L. Lee in showed that the ellipsoidal projection is finite below. This is the most striking difference between the spherical and ellipsoidal versions of the transverse Mercator projection: Features[ edit ] Near the central meridian Greenwich in the above example the projection has low distortion and the shapes of Africa, western Europe, the British Isles, Greenland, and Antarctica compare favourably with a globe.
The central regions of the transverse projections on sphere and ellipsoid are indistinguishable on the small-scale projections shown here. The more distant hemisphere is projected above the north pole and below the south pole. The equator bisects Africa, crosses South America and then continues onto the complete outer boundary of the projection; the top and bottom edges and the right and left edges must be identified i.
Distortion increases towards the right and left boundaries of the projection but it does not increase to infinity.
The map is conformal. Lines intersecting at any specified angle on the ellipsoid project into lines intersecting at the same angle on the projection.
The point scale factor is independent of direction at any point so that the shape of a small region is reasonably well preserved. The necessary condition is that the magnitude of scale factor must not vary too much over the region concerned. Note that while South America is distorted greatly the island of Ceylon is small enough to be reasonably shaped although it is far from the central meridian.
The choice of central meridian greatly affects the appearance of the projection. Direct series for scale, convergence and distortion are functions of eccentricity and both latitude and longitude on the ellipsoid:Mercator Gerhardus definition: Gerhardus Originally Gerhard Kremer.
Flemish cartographer who developed the Mercator projection (). Definitions Mercator Gerhardus. Mercator type of map projection, s, invented by Flemish geographer Gerhard Kremer (), who Latinized his surname, which means "dealer, tradesman," as Mercator (see merchant). He first used this type of map projection in Mercator projection definition, a conformal projection on which any rhumb line is represented as a straight line, used chiefly in navigation, though the scale varies with latitude and areal size and the shapes of large areas are greatly distorted.
See more. an orthomorphic map projection on which parallels and meridians form a rectangular grid, scale being exaggerated with increasing distance from the equator Also called: Mercator's projection Collins English Dictionary. Mercator projection definition is - a conformal map projection of which the meridians are usually drawn parallel to each other and the parallels of latitude are straight lines whose distance from each other increases with their distance from the equator.
Learn about the Mercator map projection – one of the most widely used and recently, most largely criticized projections. Amanda Briney takes a look at the history and development of the Mercator projection, how it works and some criticisms of the projection.
The Mercator projection is just one of many map projections but it is one of .