Geolocation for partially polarized electromagnetic sources using multiple sparsely and uniformly spaced "spatially stretched vector sensors"

A new angle-of-arrival estimation technique is developed using an array of "spatially stretched electromagnetic vector sensors" (each of which comprises a dipole triad plus a spatially displaced loop triad) for completely polarized, partially polarized and/or unpolarized incident signals. A dipole (loop) triad is composed of three identical, spatially co-located but orthogonally oriented electrically short dipoles (magnetically small loops) distinctly measuring all three electric-field (magnetic-field) components of the (possibly) partially polarized incident wave-field. The vector cross-product direction finding approach is herein generalized to allow: (1) any arbitrary displacement between the dipole triad and the loop triad comprising the six-component electromagnetic vector sensor, thereby reducing the adverse effects of inter-antenna mutual coupling, (2) any unknown temporal phase delay between the dipole triad and the loop triad (a common situation in electromagnetics), (3) the incident electromagnetic signals to be arbitrarily partially polarized or unpolarized. Simulations demonstrate the efficacy of this new technique.