Direction of arrival estimation of wide band sources with small array based on beam-space coherent signal-subspace method

With a small four-sensor planar array, the beam-space coherent signal-subspace method (BSCSM) applied to the orientation of wide-band sources is studied, and its performance analysed. Measured helicopter noise is used to simulate output of array elements as wide-band sources, which are made to have certain directions of arrival (DOA). The BSCSM, CSM (coherent signal-subspace method) and ICSM (incoherent signal-subspace method) are employed respectively to estimate sources DOAs and accurately distinguished. Performance of the proposed method is compared with other methods mentioned in this paper with computer simulation. The beam-space method provides performance better than the other two methods in terms of simulation results, error analysis, and resolution estimation of angles of arrival of multiple wide-band plane sources.