Numerical methods for wavefront analysis

The problem considered is that of calculating the angles of arrival of the components of a multimoded signal from simultaneous measurements of the signal induced in each element of a linear array. A numerical method is described in which the arrival angles are obtained from the roots of a polynomial whose coefficients are solutions of a set of linear equations. This method has been applied to determination of elevation arrival angles for multimode signals in the h.f. band, using data from a vertical array of equally spaced horizontal loops. In this case, the ground is assumed to be perfectly conducting, but the method of analysis is not restricted to this condition.