Array Invariant-Based Source Localization in Deep Sea by Vertical Linear Array

The array invariant proposed for robust source localization in shallow water is based on the dispersion characteristics in ideal waveguides for broadband signals. With minimal knowledge of the environment, the approach involves plane wave beamforming using a vertical linear array (VLA), utilizing multiple arrivals separated in pitch angle and travel time. The approach has been demonstrated successfully with experimental data in shallow water. However, it is rarely reported in the deep sea. In this paper, the generalized array invariant is extended to deep-sea environment where the waveguide invariant is variable in range. The feasibility of the array invariant-based source range estimation in deep sea is verified by 2016 South China Sea experiment data with different source-receiver ranges (3.1km and 10.8km) in 2000 m water depth. The results show that the method can be effectively applied to deep-sea localization, and the relative error is not high. This method can provide reference for the research of deep-sea localization and deep-sea target recognition.