ABSTRACT
The current Federal Communications Commission (FCC) Rules for distance calculations use two methods: flat-earth and spherical-earth. The flat-earth method assumes the distance between two points to be the hypotenuse of a right triangle whose sides are determined by the difference in latitude and longitude of the starting and ending points multiplied by the length per degree of latitude and longitude at the mid-latitude of the two points, as shown in Figure
1.7-1. The “flat-earth” term refers to the use of a right triangle to calculate the distance. Because the lengths of a degree of longitude and a degree of latitude used in the flat-earth method are derived from an ellipsoid rather than a spheroid model of the earth, the flatearth method is actually more accurate than the spherical-earth method for short to moderate distances.
