Mast-Mounted Sonar Deployment Device for Optimal Depth Positioning

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Solution Overview

Problem

Existing sonar systems deployed in coastal and port surveillance face challenges in maximizing range performance due to varying sound propagation characteristics with depth and climatic conditions, particularly in shallow waters, where reverberation limits detection range and existing fixed installations do not adapt effectively to different geographical and seasonal changes.

Innovation Solution

A deployment device for sonar systems that includes a telescopic mast with adjustable length and remote control, allowing the sonar to be positioned at optimal depth for maximum range, using bathythermal data to determine the best placement between water layers, and featuring a float for stability and easy movement, enabling omnidirectional coverage and simplified maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the sonar is fixed to the bottom of the sea on a massive support, then the installation is stable and permanent, but the detection range is limited due to reverberation from the bottom and inability to adapt to varying bathythermal conditions

Engineering Contradiction:
Improveinstallation stabilityVSAvoiddetection range
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The system divides the sonar installation into separate functional components: a stationary anchoring structure providing stability, and a movable mast with platform that can be positioned at optimal depths. This segmentation allows the sonar to achieve both stable installation and extended detection range by placing the acoustic sensor away from the reverberating seabed while maintaining permanent installation through the anchoring system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions the sonar from a two-dimensional bottom-fixed position to a three-dimensional vertical positioning system using a telescopic mast. The mast enables the sonar platform to operate at variable heights above the seabed, utilizing the vertical dimension to optimize detection range by positioning the sonar in water layers with favorable acoustic propagation characteristics.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Device complexity

If the sonar is placed close to the bottom, then the installation is simpler, but the detection range is limited by reverberation from the bottom

Engineering Contradiction:
Improveinstallation complexityVSAvoiddetection range
Core Design Contradiction:
Device complexityVSLength of moving object

Solution Approach 1:

The telescopic mast acts as an intermediary element between the seabed and the sonar platform. It provides the necessary separation distance to reduce bottom reverberation effects while maintaining a relatively simple installation structure. The mast serves as a mechanical link that enables the sonar to operate at an optimal height without requiring complex deployment mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If the mast length is fixed, then the structure is simpler, but the system cannot adapt to different geographical and climatic conditions

Engineering Contradiction:
Improvestructure complexityVSAvoidadaptability to bathythermal conditions
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The mast is designed with telescopic capability, transforming it from a static fixed-length structure to a dynamic adjustable-length structure. This allows the system to adapt to varying bathythermal conditions, seasonal changes, and different geographical locations by modifying the mast extension length, thereby optimizing sonar performance without requiring complete system replacement.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system enables parameter changes in the mast length to optimize sonar operation under different environmental conditions. By adjusting the mast extension length, the sonar platform can be positioned at depths that correspond to favorable acoustic propagation layers for specific geographical areas and seasonal conditions, as determined by bathythermal data.

Inventive Principle:
Principle #35Parameter changes

4Area of stationary object

If multiple sonar heads are deployed to cover different areas, then the area coverage is improved, but the cost and complexity increase

Engineering Contradiction:
Improvearea coverageVSAvoidnumber of sonar heads
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The invention utilizes the vertical dimension through the telescopic mast to achieve omnidirectional coverage. By positioning the sonar platform at an optimal height above the seabed, the system achieves 360-degree azimuthal coverage without requiring multiple sonar heads, thereby maintaining area coverage while reducing system complexity and cost.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 solution enhances sonar range performance by optimizing sonar placement, reducing the number of required sonar heads, and simplifying maintenance, while ensuring effective long-term surveillance across varying bathymetric conditions, resulting in improved area coverage and cost-effectiveness.

Implementation Method 1

a float arranged to be fixed on the mast, close to the top, the buoyancy of which is sufficient to maintain the mast in a vertical position

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 2

the propagation of sound waves is not rectilinear: their path has a curvature which depends in particular on variations in the speed of sound with depth

Methodology Applied
Scientific EffectSound wave propagation: Sound

Implementation Method 3

the sonar having emitted an acoustic wave can detect the signal reflected by this target

Methodology Applied
Scientific EffectAcoustic reflection: Reflection

Data Source

PatentEP2126897B1Mast-mounted sonar
Publication Date: 2017.12.13 THALES SA
  • EP2126897B1 patent drawingFigure 1
  • EP2126897B1 patent drawingFigure 2
  • EP2126897B1 patent drawingFigure 3

AI summary

The present invention relates to the general field of coastal protection and the surveillance of ports. It consists of a deployment device, for a sonar surveillance system, comprising chiefly: an anchoring structure (11), - a support mast (12) designed to be mounted on the structure (11) and arranged on the latter in such a way as to adopt a substantially vertical position, - a platform (13) mounted on the top of the mast (12) and receiving a sonar head (16), - a float (14) fixed to the mast, in proximity to the top, the buoyancy of which is sufficient to keep the mast (12) in the vertical position, when the latter is subjected to the action of movement of the water masses in which it is immersed, the length of the mast (12) is determined in such a way as to position the sonar head (16) at a depth for which the latter exhibits maximum performance in terms of detection range. It applies more particularly to the formulation and deployment of sonar systems, intended to be installed in a fixed position to carry out such protection.