Sonar Pulse Localization Using Dual Collinear Antennas
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sonar emission interception systems based on the curvature of the wavefront (CFO) face precision issues due to poor quality measurements of signal arrival times, which are affected by the propagation channel, transmission electronics, and parasitic signals, leading to a lack of robustness and requiring multiple distributed antennas with precise installation, increasing costs.
Innovation Solution
A sonar pulse localization system using two collinear antennas, where one antenna is used for detection and the other for focusing, allowing distance determination from the transmitter without the need for multiple distributed antennas, thereby improving measurement robustness and reducing installation complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple distributed antennas are used for CFO measurement, then distance determination capability is improved, but device complexity and installation precision requirements increase
Solution Approach 1:
The patent combines the functions of multiple distributed antennas into a single antenna with multiple sensors arranged in a specific geometry. The sensor array processes signals collectively to achieve the same CFO measurement capability that would require multiple separate antennas, thereby reducing system complexity while maintaining distance determination precision.
Solution Approach 2:
The single antenna with multiple sensors serves multiple functions: it performs both bearing estimation and distance determination through CFO measurement. This multi-functional design eliminates the need for separate distributed antennas, reducing installation complexity while maintaining comprehensive localization capability.
2Measurement precision
If multiple distributed antennas are used for CFO measurement, then distance determination capability is improved, but installation precision requirements increase
Solution Approach 1:
By merging multiple antenna functions into a single integrated sensor array, the patent eliminates the need for precise spatial distribution of multiple antennas. The sensors are mounted on a common structure where relative positions are fixed and controlled during manufacturing, significantly reducing installation precision requirements while maintaining CFO measurement accuracy.
3Productivity
If thresholding method is used to estimate time of arrival, then processing speed is improved, but measurement precision deteriorates
Solution Approach 1:
The patent employs an iterative refinement process where initial TOA estimates from thresholding are used to guide subsequent correlation-based refinement. The system uses feedback from the initial rough estimates to focus computational effort on the most promising time intervals, thereby improving measurement precision without proportionally increasing processing time.
Solution Approach 2:
The patent applies correlation processing selectively only to the time intervals identified by thresholding, rather than performing exhaustive correlation over the entire signal duration. This partial application of the more precise method maintains measurement accuracy while preserving the speed advantage of the thresholding approach for the majority of processing.
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
The system provides a robust and cost-effective means to determine the distance of a sonar transmitter, enhancing the accuracy of risk assessment and source kinematics evaluation without the need for multiple antennas, thus improving tactical decision-making.
Implementation Method 1
The invention relates generally to passive sonars, and in particular to a system and a method for locating emissions intercepted by such sonars
Implementation Method 2
Existing sonar emission interception systems based on the exploitation of the curvature of the wave front (CFO)
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention proposes a system (100) for locating sonar pulses for a submarine, including: - two antennas having a generally linear shape and being substantially parallel to one another (101, 102) arranged on the submarine, the two antennas including a detection antenna (101) and a focusing antenna (102), the detection antenna (101) being smaller in size in comparison to the length of the second antenna (102), each antenna including a set of sensors (1010, 1020), - at least one interception module (51) for determining the direction of a sonar transmission transmitted by a transmitter and intercepted by the detection antenna (101), and - a focusing module (52) for determining the distance of the transmitter by focusing paths from signals originating from the sensors of the focusing antenna (102), in the direction of the transmission determined by the detection module (101).