"In cartography, a map projection is any of a broad set of transformations employed to represent the curved two-dimensional surface of a globe on a plane."
Types of projection used in topography.
Geodetic Datums: A geodetic datum is a model that describes the shape of the earth and the location of points on its surface.
Map Projections: A map projection is a way of representing the curved surface of the earth on a flat map. Different projections work well for different purposes.
Coordinate Systems: A coordinate system is a set of rules that defines how points in space can be identified and located.
Cartographic Scale: Cartographic scale is the relationship between the distance on a map and the actual distance on the ground.
Legend: A legend is a guide that explains the symbols used on a map.
Contour Lines: Contour lines are curved lines on a map that represent changes in elevation.
Relief: Relief represents the 3-Dimensional aspects of the earth's surface.
Orientation: Orientation is the relationship between a map and the geographic north.
Azimuth: Azimuth is the direction of a line on a map, measured in degrees.
GIS (Geographic Information Systems): GIS is a system used to manage, analyze, and visualize spatial data.
Azimuthal: This type of projection is based on projecting the earth's surface onto a plane that is tangent to the sphere at one point, usually at either the north or south pole. It is often used to represent polar regions.
Cylindrical: This projection is based on wrapping the earth's surface around a cylinder, then projecting that cylinder onto a flat surface. It is often used for navigational and engineering purposes.
Conical: This type of projection is based on projecting the earth's surface onto a cone, then unwrapping the cone to create a flat map. It is often used for mapping mid-latitude regions.
Orthographic: This projection is based on projecting the earth's surface onto a plane that is tangent to the sphere at infinite distance. It is often used for showing the entire earth from space.
Gnomonic: This projection is based on projecting the earth's surface onto a plane that is tangent to the sphere at one point, then projecting outward from that point. It is often used for finding the shortest distance between two points on a globe.
Stereographic: This projection is based on projecting the earth's surface onto a plane that is tangent to the sphere at the equator, then projecting outward from the poles. It is often used for geologic maps.
Mollweide: This projection is based on projecting the earth's surface onto an ellipse, then stretching that ellipse to create a flat map. It is often used for showing distribution of data and climate patterns.
Robinson: This type of projection is a compromise between preserving shape and area, and is a stretched version of the Winkel tripel projection. It is often used for general-purpose world maps.
Mercator: This projection based on cylinder, is known for exaggerating the size of regions near the poles, but is extremely popular due to navigational ease.
Peters: This projection based on cylindrical, is designed to proportionalize the sizes of continents.
"In a map projection, coordinates, often expressed as latitude and longitude, of locations from the surface of the globe are transformed to coordinates on a plane."
"Projection is a necessary step in creating a two-dimensional map and is one of the essential elements of cartography."
"All projections of a sphere on a plane necessarily distort the surface in some way and to some extent."
"Different map projections exist in order to preserve some properties of the sphere-like body at the expense of other properties."
"The study of map projections is primarily about the characterization of their distortions."
"There is no limit to the number of possible map projections."
"Projections are considered in several fields of pure mathematics, including differential geometry, projective geometry, and manifolds."
"Rather, any mathematical function that transforms coordinates from the curved surface distinctly and smoothly to the plane is a projection."
"The Earth and other large celestial bodies are generally better modeled as oblate spheroids."
"The surfaces of planetary bodies can be mapped even if they are too irregular to be modeled well with a sphere or ellipsoid."
"The most well-known map projection is the Mercator projection."
"This map projection has the property of being conformal."
"However, it has been criticized throughout the 20th century for enlarging regions further from the equator."
"Equal-area projections such as the Sinusoidal projection and the Gall–Peters projection show the correct sizes of countries relative to each other."
"The National Geographic Society and most atlases favor map projections that compromise between area and angular distortion."
"such as the Robinson projection"
"the Winkel tripel projection."
"Therefore, more generally, a map projection is any method of flattening a continuous curved surface onto a plane."
"Few projections in practical use are perspective."