Multiple constraint space-time direct data domain approach using nonuniformly, semicircular and sinusoidal spaced arrays of real elements

A Direct Data Domain Least Squares (D³LS) approach is developed for multiple target detection in Space Time Adaptive Processing (STAP) and is applied on signal received from different configurations of real elements. 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. Then, we will apply the multiple constrained STAP D³LS on the compensated voltages. Numerical simulations are done using the three main methods of D³LS namely the forward, backward, and the forward-backward methods and it show that multiple beams are directed towards target directions maintaining their gains constrained along those directions.