RESEARCH INTO FADING

Hawke's Bay Tribune, Volume XXII, Issue 250, 5 October 1932, Page 4

RESEARCH INTO FADING

BRITISH EXPEDITION. Carrying on the unceasing research towards the goal of perfect radio, an expedition has st out from Norway, and will later carry out experiments in the vicinity of the North Pole. It is hoped to discover further details of the Heaviside layer—a stratum of ionised gas many miles above the earth’s atmosphere. This at least was the theory of Major Heaviside, a British scientist who discovered that radio signals were reflected to earth after travelling a certain distance into the sky. A layer of gas, impervious to wireless rays, was the only explanation compatible with known physical facts. It was proved that wireless waves projected at a certain spot towards the sky would be receivable on the earth’s surface from two directions—over a direct path from the transmitter, and again, the tinieht fraction of a second later, reflected from the Heaviside layer. If both signals were of the same strength, this double- reception would ruin reproduction, but luckily the sky wave, under ordinary circumstances, is not as powerful as the direct wave at a given spot, though strange to say, it travels farther. The ground wave is absorbed fairly quickly, but certain of the sky waves, reflected from the Heaviside layer at a very acute angle, reach the earth’s surface at a point miles beydnd the spot where the direct wave has faded out. But there are variations in the Heaviside layer—possibly physical variations —and in addition the layer is lower at night than in the daytime. This has been proved by experiment. So the British expedition, under Professor Appleton, is going to the polar regions because they wiT have protracted periods of daylight and darkness. An effort will be made to chart the Heaviside layer, and if it is successful, radio engineers may be able to overcome much of the fading and distortion at present experienced in long-distance radio.