Those familiar with the history of navigation aids may, with good reason, be reluctant to look upon any new aid as a panacea, but there appears to be no doubt that doppler will effect a revolutionary improvement in air navigation as we know it today. We have, for the first time, an aid self-contained in the aeroplane, independent of propagation conditions or weather, capable of giving position information anywhere over the globe with an accuracy certainly adequate to join the approach facilities at the destination aerodrome. Some of us not actively engaged in flying the world's routes tend to be influenced in our outlook by the navigation problems and facilities in high-density areas like western Europe, the United States or even the North Atlantic, and we are inclined to forget that this is only a very small part of the world route structure. The intensity of aviation activity in these high-density areas warrants the establishment of a network of radio beacons, ranges, VOR's and space pattern systems like Loran and Decca to bring order into the traffic flow, besides assisting the navigation of individual aeroplanes. When, however, we consider the immense distances flown by aircraft through Africa and India to the Far East and Australia, to South America and across the Pacific, to say nothing of Communist Asia, we begin to realize what a real dearth of navigation facilities there is over the globe.