Great Circle Map

Great Circle Map for ZL4KF

A Great Circle Map centered on ZL4KF in Waikouaiti. A straight line drawn on this map indicates the shortest distance between two points and is the path radio waves normally take. This is called the “short path” and conversely, the reciprocal bearing is called the “long path”. For instance, from here in the south of NZ, South Africa is to the south and is often difficult to hear and work because of the effects of the auroral zone over the South Magnetic Pole. However often the long path (75% of the Earth’s circumference) is able to be used instead. Long path propagation is common from here, especially into Europe as the antipodean point is off the coast of Portugal and so the antipodean focusing effect boosts signal levels into Western Europe by around 30db (1,000 times)