The Ultra-Short-Wave Guide-Ray Beacon and Its Application

Part I. Proceeding from the present state of the art of air navigation in the United States and in Germany, the ultra-short-wave instrument landing system in Europe is described. The fundamental principle and the technical improvements are mentioned and practical statements and views are given. Mention is made of the experience gained in the operation of the beacon. The conditions of inversion of the signals one into the other to avoid clicking are stated. The occurrence of split beams is dealt with. Their causes are explained and advice as to how to avoid such trouble is given. In the operation of neighboring beacons, disturbed zones will occur which, by choosing the proper frequency spacing and the proper selectivity of the receivers, may be restricted to such an extent that they will not impair the use of radio beacons in any way. These problems are discussed more in detail. Part II. At first the propagation of ultra-short waves is treated on the basis of the theory of combining reflection and diffraction on the earth with respect to their application to long-range navigation. It results that for a fixed distance and flying height an optimum wave length range exists allowing the airplane to cover ranges of 250 kilometers and more. The investigation of propagation results in the possibility of long-range navigation by means of ultra-short-wave beacons. The experiments made in Australia gave very encouraging results.