A deep-sea direct sound ranging method based on effective sound velocity estimation for turning ray.

The complexity of deep-sea acoustic ray bending is positively correlated with propagation distance, typically turning beyond 10 km. Existing ranging correction methods fail under turning conditions, limiting ranging accuracy. This letter proposes an effective sound velocity estimation method for turning ray, based on reliable acoustic path boundary to classify turning direct sound and establish a ray-tracing model for ranging correction. This method extends high-accuracy ranging from a 10 km scale to the first convergence zone. Experimental results demonstrate that the method achieves a positioning precision of 6.18 m at a horizontal distance of 34 km, validating its effectiveness.