Great Circle Route

Radio Amateurs often refer to the 'great circle route' between two stations, but what exactly is a 'great circle route?' The term comes from the field of mathematics. In mathematics, a great circle is a circle formed by the intersection of a sphere and a plane passing through its center. Slice the earth with a plane that simultaneously touches two stations and the center of the earth and the circle formed where the plane cuts through the circular edge of the earth is a great circle. Unless two stations are on exact opposite sides of the earth the result will be both a long great circle path and a shorter great circle path around opposite sides of the earth. ©2004 Tigertek, Inc. All rights reserved.

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