Single-Layer Sonar Modeling for Accurate Depth and Lateral Measurements
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sonar technologies for determining depth and lateral deviation in underwater environments face inaccuracies due to varying sound wave velocities with depth, requiring complex multilayer models and significant computational resources, especially with multibeam sonars.
Innovation Solution
A single-layer model is employed where sound waves propagate in a straight line with a mean velocity independent of direction, allowing for accurate depth and lateral deviation calculations using a harmonic mean velocity and propagation angle, reducing computational complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a multilayer model is used to account for sound velocity variations with depth, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent segments the complex multilayer sound velocity model into a simplified single-layer model that uses a single effective sound velocity value. This segmentation approach maintains measurement precision by focusing on the critical parameter (effective velocity) while eliminating unnecessary complexity from detailed layer-by-layer modeling.
Solution Approach 2:
The patent changes the parameter representation from multiple velocity values across different depth layers to a single effective velocity parameter. This parameter transformation simplifies the mathematical model while preserving the essential physics of sound propagation through varying media, resolving the contradiction between precision and complexity.
2Measurement precision
If point-by-point sound ray path plotting is performed to account for refraction, then measurement precision is improved, but productivity decreases
Solution Approach 1:
The patent extracts the essential refraction effect from the complex point-by-point ray tracing process. By taking out only the critical refraction correction needed for depth and lateral deviation calculations, the method achieves accurate results without the computational burden of detailed path plotting at each measurement point.
Solution Approach 2:
The patent performs preliminary calculation of the effective sound velocity and mean propagation angle before the actual depth determination. This preliminary action prepares the necessary correction factors in advance, allowing rapid computation of depth and lateral deviation without repeated complex calculations during the main measurement process.
3Measurement precision
If multilayer modeling with layer-by-layer ray path determination is used, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent merges the multiple layer-by-layer calculations into a single integrated effective velocity calculation. By combining the refraction effects across all layers into one effective velocity parameter and one mean propagation angle, the method maintains bathymetric profile accuracy while dramatically reducing computational resource requirements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method provides accurate depth and lateral deviation measurements with reduced computational requirements, meeting international hydrographic standards while simplifying calculations.
Implementation Method 1
the sound wave velocity or the gradient thereof being supposed to be constant in each layer
Implementation Method 2
the sound wave is deviated by refraction, all along its travel between the sonar and the sounded point
Data Source
AI summary
Disclosed is a method for determining a difference in depth or a lateral distance in relation to the vertical between two points of an underwater environment, in particular by measuring a propagation time of a sound wave. The determination is based on a single-layer model of the environment in which the wave is supposed to propagate in a straight line along an effective propagation direction, at a mean velocity that is independent of the propagation direction. Also disclosed is a method for determining the profile of the mean velocity based on the measurements of differences in depths per se, a determination of the local velocity profile over the variation interval of the sounded depths, and a related sonar system.