Analysis of Accuracy of Direct Digital Method of Correlative-Interferometric Direction Finding with Two-Dimensional Correlative Processing of Spatial Signal

The paper investigates the accuracy of the direct digital method of correlative-interferometric direction finding with reconstruction of spatial analytical signal in the aperture of linear antenna array. The main requirements for modern means of radio direction finding are to ensure their accuracy and noise immunity and ability to work in real time with minimum hardware expenditure. The typical operating condition of the direction finding means of random source of radio radiation as a part of modern systems of radiomonitoring is the presence of a complex electromagnetic environment, which dynamically changes. The perspective trend of the realization of radio direction finding in these conditions is the use of digital correlative-interferometric direction finders. The analytical expressions for the error variance of the estimation of signal delay and direction have been received. It has been shown that in addition to the basic classic control parameters such as the number of the direction-finding channels and the time of the radiation analysis, the error variance of the direction finding is also affected by the magnitude of the spatial shift of the correlation processing, by the view of the weighting function of the spatial digital radiation pattern and by the value of the normalized autocorrelative function. During the simulation the dependence family of the middle square deviation of estimation of the direction from the signal/noise ratio for the different values of the spatial shift is obtained. The results of the simulation have coincided with the assessment of the accuracy of the direction finding, obtained analytically.