Вестник Дагестанского государственного технического университета: Технические науки (Dec 2018)
EVALUATION OF ERRORS CAUSED BY FALURE OF ANTENNA SYSTEM ELEMENTS INAN AERODROME AUTOMATIC RADIO DIRECTION FINDER
Abstract
Objectives The aim of the study is to develop a mathematical model for determining the direction-finding error of an aerodrome automatic direction finder (ADF), depending on the position of the defective vibrator relative to the source of radio emission.Methods To determine the direction-finding error depending on the mutual location of the defective ADF vibrator and direction finding towards the radio source, the method of Fourier series expansion of step-by-step sampling of the signal phases is used. The direction-finding error is defined as the difference in the sum of the first harmonics of the phase sample’s stepped envelope Fourier expansion of the fault-free and defective antenna systems.Results In this work, a mathematical model is obtained for determining the direction-finding error of the aerodrome automatic direction finder (ADF), depending on the mutual position of the defective vibrator and direction finding towards the radio source. The graph of the alteration of the ADF direction finding error is obtained depending on the position of the defective vibrator and the direction finding towards the source of radio emission. It is shown that during ADF operating in the quasi-Doppler mode, the failure of the vibrators located along the direction finding towards the source of radio emission does not lead to an error in direction finding. Conversely, during ADF operating in the differential-phase mode, the failure of the vibrators located along the direction finding towards the source of radio emission leads to a maximum direction-finding error, reaching 3.75є.Conclusion When an aerodrome automatic direction finder (ADF) operates in a quasi-Doppler mode, the failure of the vibrators located along the direction finding towards the source of radio emission does not lead to an error in direction finding and, conversely, when the ADF operates in differential phase mode, this results in a maximum direction-finding error of 3.75є.
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