National Association of Broadcasters Engineering Handbook, 10th Edition

CHAPTER 1.7 Distance and Bearing Calculations

DANE E. ERICKSEN, P.E., CSRTE, 8-VSB, CBNT

Hammett & Edison, Inc., Consulting Engineers, San Francisco, California

INTRODUCTION

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 ...