Construction of A Map Projection
The creation of a map projection involves two steps:
- Selection of a model for the shape of the Earth or planetary body (usually choosing between a sphere or ellipsoid). Because the Earth's actual shape is irregular, information is lost in this step.
- Transformation of geographic coordinates (longitude and latitude) to Cartesian (x,y) or polar plane coordinates. Cartesian coordinates normally have a simple relation to eastings and northings defined on a grid superimposed on the projection.
Some of the simplest map projections are literally projections, as obtained by placing a light source at some definite point relative to the globe and projecting its features onto a specified surface. This is not the case for most projections, which are defined only in terms of mathematical formulae that have no direct geometric interpretation.
Read more about this topic: Map Projection
Famous quotes containing the words construction of, construction, map and/or projection:
“When the leaders choose to make themselves bidders at an auction of popularity, their talents, in the construction of the state, will be of no service. They will become flatterers instead of legislators; the instruments, not the guides, of the people.”
—Edmund Burke (1729–1797)
“There’s no art
To find the mind’s construction in the face.”
—William Shakespeare (1564–1616)
“If all the ways I have been along were marked on a map and joined up with a line, it might represent a minotaur.”
—Pablo Picasso (1881–1973)
“Those who speak of our culture as dead or dying have a quarrel with life, and I think they cannot understand its terms, but must endlessly repeat the projection of their own desires.”
—Muriel Rukeyser (1913–1980)