Map Projection is a geometric function that converts the earth’s curving, elliptical surface to a flat, two-dimensional plane.
Map projections are required for generating maps of the Earth or sections of the Earth that are shown on a plane such as a sheet of paper or a computer screen since the Earth is roughly the form of an oblate spheroid.
It is a necessary component of every modern map, and there are an endless number of map projections imaginable.
In cartography, a map projection is one of several ways for representing the three-dimensional surface (3D) of the globe or another spherical body on a two-dimensional plane (2D) (map making).
This operation is often, but not always, a mathematical procedure (some methods are graphically based).
It is created in three phases, with information lost at each step.
A) selection of a model for the earth’s or circular body’s shape (choosing between a sphere or ellipsoid)
B) Geographic coordinates (longitude and latitude) are converted to plane coordinates (eastings and northings).
C) Scale it back (in manual cartography this step came second, in digital cartography it comes last)
Major projection methods
There are several types of maps projection methods on various themes.
A. Cylindrical Map Projections
Cylindrical map projections are one method of representing the Earth.
Straight coordinate lines with horizontal parallels intersecting meridians at right angles characterize this map projection. The scale is constant along each parallel and all meridians are similarly spaced.
Cylindrical map projections are rectangles, but they are termed that because their edges can be mapped in a tube, or cylinder.
The size used to space the parallel lines on the map is the single thing that separates different cylindrical map projections from one another.
The disadvantages of cylindrical map projections include considerable distortion at the poles.
While the areas near the Equator are most likely to be correct in comparison to the actual Earth, the parallels and meridians are straight lines and cannot account for the curvature of the Earth.
B) Conic Map Projections
The equidistant conic projection, the Lambert conformal conic, and the Albers conic are all examples of conic map projections.
The cone constant, which determines the angular distance between meridians, defines these maps.
These meridians are equidistant and straight lines that converge at points along the projection regardless of whether or not there is a pole.
Conic map projections, like cylindrical projections, feature parallels that intersect the meridians at right angles with a consistent amount of distortion throughout. Conic map projections are popular.
meant to wrap around a cone on top of a sphere (globe), but not intended to be mathematically exact
Conic map projections are best suited for regional or hemispheric maps, but not for a whole global map.
C) Azimuthal Map Projection
The azimuthal is angular: given three locations on a map.
These angular connections are also known as geodesic arcs or great circle arcs.
Straight meridian lines extending out from a central point, parallels that are circular around the center point, and equidistant parallel spacing are the key characteristics of azimuthal map projections.
Light routes of three types (orthographic, stereographic, and gnomonic) may also be employed. Azimuthal maps are useful for determining direction from any place on Earth by utilizing the central point as a reference point.
All map projection methods have advantages and disadvantages, but they are highly adaptable.
Even though it is practically difficult to make a perfectly accurate map projection, even the most flawed renderings of the Earth have use.
Map projections are designed for certain reasons and should be used accordingly. In the end, every map projection has a place, and the number of projections that may be constructed is infinite.
