Space Time Adaptive Processing (STAP) using two dimensional array of real elements based on Direct Data Domain Least Squares (D3LS) approach

In this paper, STAP applied on signals from planar array of real elements using D³LS. The estimation of complex amplitude of Signal of Interest (SOI) will be difficult due to the strong mutual coupling between real elements. We have to eliminate the mutual coupling that exists between the antenna elements by using the transformation matrix. The transformation matrix converts the voltages that are induced at the loads corresponding to the feed point of the array elements to an equivalent set of voltages that will be induced by the same incident wave in Uniform Linear Virtual Array (ULVA) of isotropic point sources. A Direct Data Domain Least Squares (D³LS) Space Time Adaptive Processing (STAP) approach is presented for adaptively enhancing signals in a nonhomogeneous environment and will be applied on compensated voltages from transformation matrix. Numerical simulations are done using the three main methods of D³LS namely forward, backward, and forward-backward methods.