MODELING OF THE EFFECT OF ANTENNA ELEMENTS ARRANGEMENT INACCURACY ON THE ERROR OF THE CORRELATION INTERFEROMETRIC DIRECTION FINDER
A.I. Panychev, A.V. Maksimov, A.A. Vaganova
The main sources of instrumental errors of direction finding in means of automated radio monitoring are the design errors and the spread of the feeder path characteristics of the antenna system. In the article the direction finder realizing the principle of the correlation interferometric direction finder in which the resulting characteristic of the directionality of the ring antenna array is formed by the direct synthesis method is considered. The model of a volumetric array of linear radiators capable of taking arbitrary orientation and placed without shading each other is used. The distortions of the synthesized radiation pattern due to errors in the positioning of the antenna system elements along the azimuthal and radial coordinates are estimated. A comparative analysis of realizations of the synthesized radiation pattern of the direction finder obtained using various laws of distribution of geometric errors is carried out. Conclusions are made about the degree of influence of root-mean-square errors of antenna elements placement in azimuth and radius on the distortions of the radiation pattern. It is established that the displacement of the elements of the ring antenna array along the azimuth is more significant than radial displacement for deformation the radiation pattern. The main statistical characteristics of the direction-finding errors for both angular coordinates are calculated for different distribution laws for the errors in the placement of the elements of the antenna array. With a uniform distribution of placement errors, the hypothesis that a instrumental error in the azimuthal coordinate has a normal distribution is adopted in accordance with Pearson’s agreement criterion. In the case of a normal distribution of placement errors, the law of distribution of instrumental error in both coordinates is not normal.
Keywords: direction finder, annular array, radiation pattern, instrumental error, the direct synthesis method.