The Nature of Geographic Information

8. Geospatial Measurement Scales


The word "scale" can also be used as a synonym for a ruler--a measurement scale. Because data consist of symbols that represent measurements of phenomena, it's important to understand the reference systems used to take the measurements in the first place. In this section, we'll consider a measurement scale known as the geographic coordinate system that is used to specify positions on the Earth's roughly spherical surface. In other sections, we'll encounter two-dimensional (plane) coordinate systems, as well as the measurement scales used to specify attribute data.

In this section of Chapter 2 you will:

  1. demonstrate your ability to specify geospatial locations using geographic coordinates;
  2. convert geographic coordinates between two different formats.