Introduction - Projection Systems

Background Info:

We are all familiar with the globe as a model of earth. Since a globe is spherical like the earth, it is the most accurate representation of the earth's surface features. Large features such as continents and oceans are accurately depicted and easy to study on a globe, but globes are too small to show details such as streams, villages, or streets. To show such details, a variety of maps have been developed.

The earth's curved surface can not be accurately transferred onto a flat surface such as a map. Transferring a curved surface to a flat map results in distortion of the surface features. The features of the surface get distorted not only in size and shape, but distances and directions also get altered. The larger the area being shown, the greater the distortion. As a result, a map showing the entire world has the greatest distortion, while a map of a small area is fairly accurate.

The Objectives of this Module are to::

• Define map projection.

• Describe the three types of projection methods.

• Compare and contrast the distortions that result from each type of projection system.

What are map projections? What different types of map projection systems are there? How do the different types of projection systems change the way we see the world?