Improvement of 2-D direction finding algorithm of coherent signals based on two L-shape arrays

This paper presents an improved method of two-dimensional (2D) direction finding for coherent signals based on two L-shape arrays. A new type of three-dimensional (3D) direction angles has been defined in this method. The proposed method decorrelates the coherent incident signals and reconstructs the signal subspace using the cross-correlation matrix. Then the shift invariance property of the array geometry is employed to estimate the angle along each coordinate axis. All estimated angles got pair-matched by spatial relationships of their direction cosines, and weighted least-square (WLS) method is used to refine the estimated angles. Simulation results show that the proposed method, compared with the conventional methods, has higher estimation accuracy and is not sensitive to direction-of-arrival (DOA).