Frequency-shift compensation localization method for large aperture horizontal array in shallow water

The interference of different normal mode makes the horizontal longitudinal correlation of sound field oscillate. The frequency-shift compensation relationship between the received signals at different positions is derived by using the horizontal distance-frequency interference structure, combined with the characteristics of high dispersion of spatial distribution of large aperture array elements, a localization method suitable for slowly varying spectrum signal is proposed. By using the change of the frequency-shift compensation with the position of sound source, the ambiguity plane of two elements is superimposed to realize the horizontal two-dimensional plane localization. The simulation results show that the method has good localization performance and good tolerance to environmental parameter mismatch. The linear phase relationship after frequency-shift compensation effectively improves the correlation between the received signals, thereby improving the processing gain of the large aperture array. The aperture advantage of the array improves the spatial resolution, and the peak-to-background ratio of the ambiguity plane is high. Sea trial data validation shows that the average relative deviation of 10−80 km ranging results is 5.68% and the average distance deviation of localization results in two-dimensional plane is 0.78 km.