Computationally efficient two-dimensional direction-of-arrival estimation of electromagnetic sources using the propagator method

The authors develop a propagator-based algorithm for two-dimensional (2D) direction finding of electromagnetic sources under spatially correlated noise here. The planar-plus-an-isolated array geometry, first defined by Li et al. (1996) is adopted. The authors propose to replace the planar pressure-sensors in Li et al. (1996) by electromagnetic vector sensors, thus exploiting the benefits inherent in the additional measurements made by a vector sensor. Compared with the algorithm in Li et al. (1996), the presently proposed algorithm can offer closed-form automatically paired azimuth-elevation angle estimates, without costly 2D iterative searching. Moreover, the proposed algorithm can achieve the unambiguous direction estimates with enhanced accuracy by setting the planar electromagnetic vector sensors to space much farther apart than a half-wavelength. Therefore the proposed algorithm constitutes a distinct improvement over (Li et al., 1996).