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Explain the difficulties associated with representing a spherical shape on a flat surface.

There are several problems with trying to flatten a round object, and these problems become apparent during map making.

These are:

  • Shapes become distorted
  • Size is not constant.
  • Angles are not constant.
  • Chart Distance : Earth Distance is not constant.

To try to correct for some of these issues we use mathematical equations to pull everything back to shape and size. Once this has been achieved the map is called an Orthomorphic chart. This process only minimizes the distortion; it can never be fully eliminated.

Describe the process of creating a Mercator projection

Mercator chats are created by wrapping a reduced earth with a cylinder and projecting a light from the centre of the earth

Describe the process of creating a Lambert's conformal projection.

A cone is projected onto the earths surface which cuts the surface in 2 places, called standard parallels. 

The mapped area of the chart lies inside the earth between the 2 standard parallels.

Detail of the standard parallels are printed on aeronautical charts

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