Arrangement for correcting deviations from the true bearing caused by reflecting surfaces in target tracking radar installations

Claim 1

An arrangement for correcting deviations from the true bearing due to the effects of specular reflecting surfaces in target tracking radar installations comprising at least three primary feeds, at least two of said primary feeds being aligned such that a plane formed by the longitudinal axes of their radiation characteristics is disposed at least approximately perpendicular to the specular reflecting surface, and at least one further primary feed is arranged such that the longitudinal axis of its radiation characteristic is located externally of such plane, a summation-difference network which produces from the echo signals received by the primary feeds a summation signal, two difference signals, and a cross-term signal formed in at least one measurement interval, means for forming a corrected angle error signal F e from these signals and which angle signal is divided into two components, a signal processing stage for forming a correction signal F.sub.Δ in order to correct the angle error signal E EP falsified by the reflection effects F.sub.E (X.sub.1) = E.sub.EP + F.sub.Δ the correction signal F.sub.Δ being expressed by the following equation F.sub.Δ = -E.sub.EQ /E.sub.KQ E.sub.KP + F.sub.ΔR wherein E ep = the angle error signal portion falsified by specular reflection effects and in phase with the summation signal; E eq = the angle error signal falsified by the specular reflection effects and in quadrature to the summation signal; E kp = the angle error signal portion obtained from the cross-term function and in phase with the summation signal; E kq = the angle error signal portion obtained from the cross-term function and in quadrature to the summation signal; F.sub.Δr = residual correction signal; and F e (x 1 ) = the angle error signal after correction.