Laser Warning Receiver Iterative Angular Resolution
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Solution Overview
Problem
Current laser warning receivers struggle to detect very low power laser sources with high angular resolution due to high background radiation from sunlight, limiting their ability to effectively locate and counter low power laser beam rider threats.
Innovation Solution
A laser warning receiver system incorporating a detection channel with a fixed field-of-view and optical filters, coupled with a pulse analyzer circuit and a liquid crystal display matrix for iterative localization, allowing for variable direction of regard and field-of-view adjustment to isolate and pinpoint low power laser sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a narrow-band filter is used to reduce background radiation and achieve low detection threshold, then detection sensitivity is improved, but angular resolution is limited to a quadrant
Solution Approach 1:
The field of view is divided into multiple quadrants, with each quadrant containing a separate photodetector element. By segmenting the detection array into N×M elements arranged in different angular sectors, the system achieves both high sensitivity (through narrow-band filtering) and high angular resolution (through spatial segmentation across multiple quadrants).
Solution Approach 2:
The invention transitions from single-quadrant detection to multi-quadrant spatial arrangement, adding angular dimensionality to the detection system. The N×M photodetector array elements are positioned at different angular sectors, enabling the system to resolve laser sources in multiple directions simultaneously while maintaining detection sensitivity through optical filtering.
2Reliability
If dedicated wide field-of-view high-gain modules are used for each quadrant to detect laser beam rider sources, then detection capability is improved, but angular resolution remains poor (worse than quadrant level)
Solution Approach 1:
Each quadrant is further segmented into multiple photodetector elements (N×M array), allowing the system to maintain wide field-of-view coverage while achieving fine angular resolution. The segmentation enables independent detection and localization of laser sources in different angular sectors with high precision.
Solution Approach 2:
The system dynamically adjusts the active detection elements based on the detected laser source position. By selectively activating specific photodetector elements in the N×M array, the system optimizes angular resolution for the specific direction of the laser threat while maintaining overall wide field-of-view coverage.
3Reliability
If a gated video camera system with high angular resolution is used to detect very low power laser sources, then detection sensitivity and angular resolution are improved, but system complexity and cost increase significantly
Solution Approach 1:
The invention replaces expensive gated video camera systems with a more economical photodetector array system. By using multiple inexpensive photodetector elements arranged in an N×M configuration with simple optical filtering, the system achieves comparable or superior performance without the high cost and complexity of gated camera technology.
Solution Approach 2:
The invention substitutes the mechanical gating mechanism of video cameras with an electronic signal processing approach. The photodetector array continuously samples laser signals, and electronic circuitry selectively processes signals from specific elements based on detected laser positions, eliminating the need for mechanical shutters and complex video timing systems.
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
Enables simultaneous low detection threshold, wide field-of-view, and high angular resolution for effective localization of very low power laser sources, reducing complexity and cost while maintaining operational capability from bright sunlight to moonless nights.
Implementation Method 1
an optical filter arrangement before a photodetector to detect any incoming signals consisting of a laser beam
Implementation Method 2
a lens having a similar field-of-view (FOV) as in the detection channel which focuses that FOV onto a N×M element liquid crystal display (LCD) matrix
Implementation Method 3
each element in he LCD matrix is controlled by a pattern selector connected to the pulse analyzer circuit, the selector being connected to the matrix, transparent elements in the matrix allowing a laser beam to be transmitted to the second detector
Implementation Method 4
an optical filter arrangement before a photodetector to detect any incoming signals consisting of a laser beam
Data Source
AI summary
A laser warning receiver (LWR) to detect a very low power laser beam for a laser beam rider and provide a high angular resolution in determining the angle-of-arrival of that beam. An aperture having a fixed field-of-view (FOV) is located in a detection channel followed by a narrow-band filter and a detector whose output is applied to a pulse analyzer circuit. A localization channel with the same FOV has a similar narrow-band filter and a lens to focus light from that FOV onto a detector through a N×M element LCD matrix, an output of that detector being applied to the pulse analyzer circuit whose output is applied to a LCD pattern selector connected to the matrix which controls elements in the matrix to provide a transparent window of variable size and position. The size and position of that window allows a laser beam to reach the detector, the window being iterative reduced in size when a beam is detected to provide the location of its source.