Cartography The geographic coordinate system basically refers to longitudinal and latitudinal lines and the reference points on them. The lines of longitude and latitude are based on the Earth's polar axis. Latitude lines are parallel to the equator, and are measured in degrees, with the equator's value set at 0 degrees. From the equator to each of the poles there are ninety latitude lines, for a total of 180. Latitudes north of the equator are distinguished from lines south of the equator, which divides the earth into the north and south hemispheres. Latitude lines are parallel to the Earth's polar axis and are therefore also referred to simply as parallels.

Longitude lines are perpendicular to latitude lines. They are drawn parallel to the arbitrarily created Prime Meridian, which runs through Greenwich, England and therefore establishes the reference point for international time zones as well. Like latitude lines, longitude lines are also measured in degrees. There are a full 360 longitude lines on the globe, but the maximum value of a longitude line is 180, denoted by the International Date Line. The International Date Line is therefore halfway around...

Longitude lines west of the Prime Meridian are deemed part of the Western Hemisphere, and those East are part of the Eastern Hemisphere and are denoted as such: 60 degrees West.
2. The Universal Transverse Mercator (UTM) grid system, unlike the geographical coordinate system, is based on a flat rectangular and metric coordinate system. First the Earth is modeled according to the Transverse Mercator projection system into a two-dimensional image. Then the Earth is divided into sixty segments of six degrees longitude each. Measurements start at the International Date Line. Therefore, the UTM system relies on the geographic coordinate system for its points of reference. The UTM system is displayed on most topographical and geological survey maps in North America.

3. Map scale is a ratio between the actual distance between two points on Earth and the distance between those two points as represented on the map. Map scales vary considerably. Measuring distances using a map can be done simply using a ruler and then converting the measurement to actual distance using the map's scale ratio. However, this only…