Measurement of radiation patterns of aircraft antennas in non-steady flight

Methods for measuring radiation patterns of aircraft antennas are described. During pitch and roll maneuvers radiation in the symmetry respective lateral plane of the aircraft is recorded. Diagrams of the horizontal plane are obtained by a semi-stationary method; a circular track with wings level is flown at a relatively large distance from the ground station. During the time that the maneuvers are being carried out only small parts of the ground antenna diagram are needed and the effect of the shape of this pattern is reduced to a scale factor; the brief time involved also minimizes the influence of a varying distance, changes in environment conditions, and of equipment characteristics, The effect of reflection from the Earth's surface is reduced by the use of an artificial ground plane and by optimization of the configuration of the receiving antennas. The methods were applied to a Fokker F-27 transport aircraft in a version containing nine different aerials. A fair reduction in flying time is obtained over the well-known standard method of 'flying along'.