Direction finding using an adaptive null tracker

Signals received by a multiple-element array can be processed by an adaptive null steering algorithm which treats the `signals¿¿ as `jammers¿¿, thereby potentially forming discrete nulls in the directions of arrival of individual signal components. Use of a null tracker can therefore be proposed as a means of direction finding, and, since the null widths can be made narrower than the width of a beam formed by the same aperture, it can be asserted that such a technique will achieve better resolution than conventional methods. The improved performance potentially available with the technique is compared with an exemplary convention method. The extent to which this potential can be approached is assessed in the light of receiver channel errors, finite-time averaging of the received data and the degree of correlation between received signals. Some results of experimental work are included.