Multi-Array Optical Seeker for Long-Range Laser Detection
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Solution Overview
Problem
Existing semiactive laser guidance systems face challenges in detecting and tracking illuminated targets at long ranges due to low signal-to-noise ratios, as the scattered laser energy becomes lost in environmental noise, making it difficult to maintain precision guidance in GPS-denied environments.
Innovation Solution
An optical seeker assembly with multiple linear arrays of optical detectors, including optical waveguides, bandpass filters, and linear detector arrays, combined with signal processing units to enhance detection sensitivity and improve signal-to-noise ratios through multipixel signal integration and correlation techniques, utilizing a constant false alarm rate threshold to reduce false alarms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single linear detector array is used, then the device complexity is reduced, but the detection sensitivity and signal-to-noise ratio deteriorate at long ranges
Solution Approach 1:
The detection system is divided into multiple independent linear detector arrays (first, second, third, and fourth arrays) positioned at different orientations. Each array independently processes signals from specific angular sectors, allowing the system to maintain low individual array complexity while achieving high overall detection sensitivity through combined multi-array processing.
2Measurement precision
If multiple linear detector arrays are used, then the signal-to-noise ratio and detection sensitivity are improved, but the device complexity increases
Solution Approach 1:
Signals from multiple linear detector arrays are merged and processed together through a unified signal processing system. The processing unit combines pixel intensity signals from all arrays, applies correlation processing across arrays, and integrates results to achieve enhanced signal-to-noise ratio while managing complexity through systematic combination rather than separate independent processing chains.
Solution Approach 2:
The system transitions from single-array one-dimensional processing to multi-array multi-dimensional processing. By arranging arrays at different orientations and processing signals across multiple spatial dimensions, the system achieves superior detection sensitivity and angular resolution without proportionally increasing processing complexity, as the additional dimension provides redundant information that enhances signal detection.
3Speed
If a fixed detection threshold is used, then the processing speed is maintained, but the false alarm rate increases in varying environmental conditions
Solution Approach 1:
The detection threshold is made dynamic rather than fixed. The system continuously monitors the statistical properties of received signals and automatically adjusts the detection threshold based on current environmental conditions, noise levels, and signal characteristics. This dynamic adaptation maintains high processing speed through automated adjustment while significantly reducing false alarms by matching the threshold to actual operating conditions.
Solution Approach 2:
The system implements feedback mechanisms where detection results and signal statistics are fed back to the threshold setting mechanism. The processing unit analyzes detected signals, determines noise characteristics and signal strength, and uses this feedback information to optimize the detection threshold in real-time, creating a closed-loop system that balances speed and reliability.
4Measurement precision
If signal integration across multiple pixels is performed, then the detection sensitivity is improved, but the processing time and computational load increase
Solution Approach 1:
The system performs signal integration selectively rather than comprehensively across all pixels. Instead of integrating signals from every pixel in every array, the system identifies regions of interest and performs integration only on relevant pixel groups that show potential signal characteristics. This partial integration approach maintains high detection sensitivity for actual targets while reducing unnecessary processing time and computational load on background regions.
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 enhances detection sensitivity and accuracy, allowing for precise tracking of targets at longer ranges by improving the signal-to-noise ratio and reducing false alarms, thereby improving the guidance system's effectiveness in hostile environments.
Implementation Method 1
an optical waveguide configured to receive an optical signal
Implementation Method 2
a bandpass optical filter having a bandwidth, wherein a laser beam wavelength is within the bandwidth, and configured to filter the optical signal
Implementation Method 3
a linear optical detector array optically coupled to the optical waveguide, the linear optical detector array comprising a plurality of pixel detectors to convert the optical signal and produce a plurality of pixel intensity signals
Data Source
AI summary
An optical seeker assembly and method, used in a semiautomatic laser seeker system in a precision guided munition, improve detection sensitivity, increase detection speed, and reduce calculation overhead includes at least two linear optical detector arrays, where the detection signals with the maximum summed intensity, from among pairs of adjacent pixel detectors, are selected for each linear optical detector array, and the signal with the maximum summed intensity, from among the selected signals, for pairs of adjacent linear optical detector arrays is selected, and compared to a threshold value that is set to produce a constant false alarm rate, to produce a detection signal that is then confirmed as a confirmed detection through process of correlation with other recent detection signals.