Analysis of Long Wave Polarisation Direction Finding Based on Three‐Axis Magnetic Antenna Array

ABSTRACT

To overcome the degradation of conventional direction‐finding accuracy for VLF and LW signals caused by sky‑wave‑induced polarisation deflection, this paper employs a tri‑axial magnetic antenna to capture the three‑dimensional magnetic field components and proposes an analytic closed‑form joint estimation algorithm. The direction‑of‑arrival angles and polarisation parameters are solved through eigen‑decomposition of the covariance matrix, vector cross product and polarisation projection. Simulations verify that the algorithm effectively circumvents the systematic errors introduced by elliptical polarisation, yields direction‑finding performance markedly superior to that of the conventional amplitude‑comparison method, exhibits good low‑SNR adaptability and can satisfy the engineering requirements of ship navigation and radio sounding.