A Method for Estimating the Direction of Arrival of Waves Across the Ice Layer Based on Wavenumber Asymptotic

Abstract In addressing the problem of direction estimation for underwater targets across the ice layer, this paper starts from the propagation theory of simple harmonic waves beneath the ice layer. It theoretically deduces and analyzes the impact of different incident signal angles on the direction estimation of wave arrivals across the ice layer. When the incident angle of the acoustic signal in the water beneath the ice is large, the group velocity of simple harmonic waves with different wavenumbers causes the main lobe width of conventional beamforming to broaden significantly, leading to a noticeable decrease in direction estimation accuracy. Based on the theoretical analysis, this paper proposes a method for estimating the direction of wave arrivals across the ice layer based on wavenumber asymptotic. Simulation results verify that this method can effectively achieve direction estimation across the ice layer, and the estimation accuracy has been significantly improved compared to conventional beamforming.