High accuracy 2D angle estimation with extended aperture vector sensor arrays

A novel ESPRIT-based 2D angle estimation scheme is proposed involving the use of a right-triangular array of three vector sensors spaced much farther apart than a half-wavelength. A vector sensor is composed of six co-located antennas distinctly measuring all six electromagnetic field components of a multi-component incident wavefield. Information on each source´s respective electromagnetic field components is obtained by decoupling the signal eigenvectors via lower dimensional eigenvectors derived from TLS-ESPRIT. This facilitates estimation of each source´s respective Poynting vector thereby enabling one to resolve the phase ambiguities in ESPRIT´s eigenvalues when the intervector-sensor spacing is greater than a half-wavelength. Simulations are presented showing the sample variance of the direction cosine estimates decreasing linearly on a log-log scale as the intervector-sensor spacing is increased from a half-wavelength to 30 wavelengths, with a factor of 80 reduction in the latter case relative to the former case. The proposed scheme and attendant vector sensor array also outperform a uniformly-spaced array of scalar sensors with the same aperture and same number of component antennas whenever the intervector sensor spacing in the former case is greater than 3 half-wavelengths