Unitary ESPRIT-based DOA estimation using sparse linear dual size spatial invariance array

We consider the direction-of-arrival estimation problem with a particular class of sparse linear arrays, composed of multiple widely separated subarrays. A new unitary ESPRIT- based direction-finding approach is proposed for such class of sensor arrays. The unambiguous estimates of direction cosines based on a half-wavelength baseline (invariance) and ambiguous ones based on a larger baseline are combined to obtain a better estimation accuracy. Simulation results show that proposed technique outperforms the original unitary ESPRIT which is used together with a ULA