Underwater Acoustic Reflector Identification via Multi-Parameter Sonar Analysis
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Solution Overview
Problem
Existing methods fail to accurately identify and locate underwater acoustic reflectors due to limitations in characterizing their unique features and determining their absolute position, especially when attached to structures like pipelines.
Innovation Solution
A method involving acoustic interrogation to measure 'acoustic diameter', target strength, acoustic width, frequency response, and phase response of potential reflectors, combined with multiple observations and comparison to known reflectors, to confirm their identity and location, and plotting their absolute position using geographic information systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If acoustic interrogation is used to detect underwater reflectors, then the ability to identify reflectors is improved, but the difficulty of detecting and measuring their characteristics increases
Solution Approach 1:
The patent segments the identification process into multiple distinct measurement steps: measuring target strength, acoustic diameter, acoustic width, frequency response, and phase response. Each measurement targets a specific characteristic of the reflector, allowing systematic identification through cumulative evidence rather than attempting to measure all properties simultaneously.
Solution Approach 2:
The patent utilizes changes in acoustic parameters (frequency, amplitude, phase) of the reflected signals to identify reflector characteristics. By analyzing how the reflector modifies the incident acoustic wave across different frequencies and angles, the system extracts unique identification features that distinguish reflectors from other objects.
2Measurement precision
If multiple measurement parameters are used to identify reflectors, then the precision of identification is improved, but the device complexity increases
Solution Approach 1:
The patent employs a multi-functional acoustic interrogation system that can measure multiple parameters (target strength, acoustic diameter, acoustic width, frequency response, phase response) using the same basic sonar hardware. The system achieves universal identification capability by processing different aspects of the acoustic signal through various analysis methods rather than requiring separate dedicated devices for each measurement.
Solution Approach 2:
The patent uses the acoustic signal itself as an intermediary carrier that encodes multiple reflector characteristics. By analyzing different properties of the reflected acoustic wave (amplitude, time delay, frequency content, phase), the system extracts multiple identification parameters from a single interrogation event, reducing the need for multiple separate measurement systems.
3Measurement precision
If absolute position plotting is implemented, then the location accuracy is improved, but the loss of time for processing increases
Solution Approach 1:
The patent performs preliminary measurements of multiple reflector characteristics (target strength, acoustic diameter, acoustic width, frequency response, phase response) and stores them in a database for comparison. When a reflector is detected, the system compares the measured parameters against pre-stored reference data to rapidly confirm identification and determine position, avoiding the need for complex real-time calculations and reducing processing time.
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 enables precise identification, categorization, and location of underwater acoustic reflectors, distinguishing them from other objects and accurately mapping their position, even when attached to structures, by leveraging their unique acoustic properties.
Implementation Method 1
an incident acoustic wave is partially reflected by the front of the reflector and partially pass into the core to be reflected from the shell at the rear of the reflector
Implementation Method 2
an incident acoustic wave is partially reflected by the front of the reflector and partially pass into the core to be reflected from the shell at the rear of the reflector
Data Source
Figure 1A~1C
Figure 2~3
Figure 4~5
AI summary
A method of identifying and locating an acoustic reflector is described by interrogating underwater objects with a sonar and deploying one or more of the steps of a. identifying objects that apparently reflect the acoustic interrogation with a double echo, measuring the separation of the two echoes and comparing those measurements with anticipated measurements for underwater acoustic reflectors that may be present in the search area, and accepting or rejecting the reflected acoustic wave as potentially including the echo from the front of such an acoustic reflector and the echo from the shell at the rear of the reflector; b. measuring the target strength of the echoes in a double echo received from an object and rejecting the object as one of interest if the target strength in the first echo of a double echo exceeds that of the second echo; c. measuring the total target strength of an echo from an object, the object being rejected as being a potential underwater acoustic reflector of interest if the target strength is less than a predetermined minimum; d. measuring the acoustic width of an object and comparing that with the acoustic width of known acoustic reflectors, the object being rejected as being potentially an underwater acoustic reflector of interest if the acoustic width is not that of a known underwater acoustic reflector; e. measuring the frequency response of an object, the object being accepted or rejected as being potentially an acoustic reflector of interest if the frequency response corresponds to the known frequency response of such an underwater reflector; and f. measuring the phase response of an object, the object being accepted or rejected as potentially an underwater acoustic reflector of interest if the phase response corresponds to the known phase response of such an underwater acoustic reflector. The target is being rejected as being an acoustic reflector of interest if the measured characteristics do not match the known characteristics of a reflector of interest. The selected steps can be carried out sequentially, concurrently or a mixture of the two. The selected steps may be repeated carried out several times (typically at least three). The results of each repetition are compared before a potential target reflector is selected as being one of interest. The technique allows the location of underwater structures and pipelines to be mapped.