Map Projection - Scale

Scale

A globe is the only way to represent the earth with constant scale throughout the entire map in all directions. A map cannot achieve that property for any area, no matter how small. It can, however, achieve constant scale along specific lines.

Some possible properties are:

  • The scale depends on location, but not on direction. This is equivalent to preservation of angles, the defining characteristic of a conformal map.
  • Scale is constant along any parallel in the direction of the parallel. This applies for any cylindrical or pseudocylindrical projection in normal aspect.
  • Combination of the above: the scale depends on latitude only, not on longitude or direction. This applies for the Mercator projection in normal aspect.
  • Scale is constant along all straight lines radiating from a particular geographic location. This is the defining characteristic of an equidistant projection such as the Azimuthal equidistant projection. There are also projections (Maurer, Close) where true distances from two points are preserved.

Read more about this topic:  Map Projection

Famous quotes containing the word scale:

    There is something in us, somehow, that, in the most degraded condition, we snatch at a chance to deceive ourselves into a fancied superiority to others, whom we suppose lower in the scale than ourselves.
    Herman Melville (1819–1891)

    The poet is the person in whom these powers are in balance, the man without impediment, who sees and handles that which others dream of, traverses the whole scale of experience, and is representative of man, in virtue of being the largest power to receive and to impart.
    Ralph Waldo Emerson (1803–1882)

    It is in vain that we would circumscribe the power of one half of our race, and that half by far the most important and influential. If they exert it not for good, they will for evil; if they advance not knowledge, they will perpetuate ignorance. Let women stand where they may in the scale of improvement, their position decides that of the race.
    Frances Wright (1795–1852)