A. V. Ashihmin, Yu. G. Pasternak, Yu. A. Rembovskiy

To evaluate a bearing for a given emitter using the antenna array comprising vertically oriented vibrators, a phase correlation method is often applied. This method is based on calculation of factor of the maximum correlation between measured phase distribution of a given EM field and calculated phase resistance. When antenna array elements are mounted on a mobile or vehicle-born carrier, use of reference phase distribution corresponding to plane EM wave in a free space can cause significant direction finding errors amounting up to and more. To correct direction-finding errors caused by diffraction, there are several methods to calibrate measured (or calculated) phase values depending on frequency and angular coordinates. If it is possible to fully compensate for the direction finding error (when the residual direction finding error reduces to ), this approach will require rather long databases. In this work we propose a less consuming method to compensate for direction finding error. This method is based on finding of virtual antenna array coordinates and corresponding to phase centers (or, otherwise, emission centers) of mobile or vehicle-born antenna array elements. The proposed method is based on an original way of approximation of field measurements of dependencies between voltage phases pertaining to antenna array vibrators for a finite range of EM-wave angle of incidence within a given frequency band. Its distinguishing feature is that there is no need to use or save dependencies between antenna vibrator voltage phases and azimuth angle for each discrete frequency value within the operating range. Therefore such a method can significantly increase instrumentation accuracy of mobile radio direction finders without tangible prejudice to their throughput. This work demonstrates effectiveness of the proposed method to increase instrumentation of mobile radio direction finders. It was demonstrated that there was a possibility to optimally select coordinates of auxiliary (virtual) antenna array and thus to significantly reduce direction finders systematic errors.