Direct data domain least squares (D3LS) STAP approach on signals from nonuniformly, semicircular and sinusoidal spaced arrays of real elements

In this paper, Space Time Adaptive Processing (STAP) applied on signal received from different configurations of real elements using D³LS. We are interested in three different kinds of antenna configuration which are non-uniformly spaced linear array, semicircular array and sinusoidal spaced array. The mutual coupling between real elements will affect on the estimation of complex amplitude of Signal of Interest (SOI). It is necessary to use a transformation matrix to compensate for the strong mutual coupling that exists between the antenna elements. The transformation matrix converts the voltages that are induced at the loads corresponding to the feed point of the array to an equivalent set of voltages that will be induced by the same incident wave in Uniform Linear Virtual Array (ULVA). Then, we will apply D³LS STAP on the compensated voltages. Numerical simulations are done for the three configurations using three main methods of D³LS namely forward, backward and forward-backward methods.