accuracy of estimations of bearing
correlation matrix of input signals
method of spatio-temporal signals processing
A. Boukerroum V. A. Pavlov, S. V. Pavlov
Interferometric method of direction-finding is broader applicable with the use of methods of the spatio-temporal signals processing (STSP), based on the analysis of eigenvalues structures (ES) of the covariance matrix of signals (CMS), ensures the high accuracy of the estimations of bearing only at good conditionality CMS, which is reduced with an increase in the spread of the levels of input influ-ences.
In the article are substantiated the propositions for an increase in the accuracy of the estimations of bearing on the basis of the anal-ysis of the eigenvalues of CMS in a complex signal-noise situation (SNS) with the large spread of the levels of input influences. Results are obtained under the assumption, that signals between themselves and noise in the antenna elements are not correlated.
The basis of the approach is the formation of differential CMS, obtained via the delay of formed CMS down a certain time interval and subtraction based on the current matrix of that delayed. Differential CMS is zero when the number of influencing signals on the antenna-feeder system has varied. The analysis of the elements allows to estimate the energetical, temporal, spatial and spectral parameters of the signal which has changed SNS.
The accuracy of estimating the parameters of the signals is enhanced by the fact that the differential CMS contains information only on one signal, which has changed the SNS. This is analogous to improving the Signal-to-(signal + noise) ratio. Besides, a nonzero differential CMS stipulated better, than the summarized matrix of input signals that allows obtaining estimations of the spatial parameters of radio radiation by analysis of ES of differential CMS. In addition, it is ensured decrease of quantity and complexity of mathematical operations in comparison with known methods of matrices resolution. This also ensures an increase in the accuracy of estimations due to the decrease of a quantity of operations performed by processor.