Laser Spot Stabilization via Shared Optical Path Turbulence Compensation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

High-energy laser beams are affected by atmospheric turbulence, leading to deflection and degradation of the radiation spot on distant targets, which existing methods fail to effectively stabilize due to noise from temporal surface brightness variations and image smearing, resulting in impaired target destruction efficiency.

Innovation Solution

A method and device that utilize an image acquisition device to compare reflected radiation from a target object with previous images or database entries, generating correction signals for an optical correction device to stabilize the high-energy laser beam, compensating for turbulence effects by combining filter and fine tracking controller inputs, allowing for real-time compensation without additional equipment like wavefront sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional image processing methods (center of gravity, correlation, contour tracking) are used to detect turbulence, then the radiation spot stabilization is attempted, but temporal variations in surface brightness are interpreted as virtual turbulent movements generating additional noise that significantly impairs stabilization

Engineering Contradiction:
Improveturbulence detection precisionVSAvoidradiation spot stabilization reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces an illumination laser as an intermediary light source that actively illuminates the target object. By comparing the illuminated target image with a reference image of the same target under different atmospheric conditions, the system separates actual turbulence effects from surface brightness variations. The illumination laser creates a controlled light source that allows differential measurement, where only changes caused by atmospheric turbulence are detected, not intrinsic target brightness variations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If additional sensors and transmitters (guide stars, tip-tilt laser spots, adaptive optics) are used to detect turbulence, then turbulence detection capability is improved, but device complexity and equipment outlay increase significantly

Engineering Contradiction:
Improveturbulence detection precisionVSAvoidequipment complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent makes the image acquisition device perform multiple functions: it serves both as the primary imaging sensor for target observation and as the turbulence detection sensor by capturing images under illumination from the illumination laser. The same optical path and detector are used for both target imaging and atmospheric turbulence measurement, eliminating the need for separate guide stars, tip-tilt sensors, or adaptive optics systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses its own illumination laser and image acquisition device to detect turbulence, making the system self-sufficient. The illumination laser that is already part of the imaging system serves dual purposes: providing light for target visualization and creating the reference illumination pattern needed for turbulence detection through image comparison.

Inventive Principle:
Principle #25Self-service

3Loss of information

If image acquisition is used to observe the target for turbulence compensation, then turbulence information is obtained, but temporal variations in surface brightness and image smearing generate additional noise that impairs radiation spot stabilization

Engineering Contradiction:
Improveturbulence information lossVSAvoidradiation spot position measurement precision
Core Design Contradiction:
Loss of informationVSMeasurement precision

Solution Approach 1:

The patent captures a reference image of the target object under stable atmospheric conditions before the actual laser engagement. This reference image serves as a baseline that contains the true target structure without turbulence distortion. During active stabilization, the illuminated target image is compared against this pre-captured reference, allowing the system to identify and compensate for turbulence-induced deviations while ignoring permanent target features.

Inventive Principle:
Principle #10Preliminary action

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 approach enables robust turbulence estimation and compensation, maximizing laser energy on the target with reduced irradiation time, while minimizing noise and equipment outlay, effectively maintaining a stable radiation spot for rapid target destruction.

Implementation Method 1

The propagation of high-energy laser beams in the atmosphere is subject to turbulent disturbances that are caused by temperature fluctuations and thus slight fluctuations in the refractive index of the air

Methodology Applied
Scientific EffectAtmospheric turbulence: Turbulence

Implementation Method 2

slight fluctuations in the refractive index of the air

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 3

an optical correction device which is arranged in the optical path traversed jointly by the high-energy laser beam and the reflected radiation and which can be controlled by the control device

Methodology Applied
Scientific EffectOptical path correction:

Data Source

PatentEP3034984B1Method and device for locally stabilizing a radiation spot on a remote target object
Publication Date: 2020.04.15 MBDA DEUTSCHIAND GMBH
  • EP3034984B1 patent drawingFigure 1
  • EP3034984B1 patent drawingFigure 2
  • EP3034984B1 patent drawing

AI summary

A method for locally stabilizing a radiation spot (S) on a distant target object (Z), wherein the radiation spot (S) is formed by a high-energy laser beam (L) directed onto the target object (Z) by a high-energy radiator (1), and wherein the target object (Z) is illuminated by an illumination beam (B) directed onto the target object (Z) by an illumination device (2); characterized in that radiation (B') reflected from the target object (Z) illuminated by the illumination beam (B) is received by an image acquisition device (3); that the radiation (B') reflected from the target object (Z) to the image acquisition device (3) travels through the same optical path (P) as the high-energy laser beam (L);that the image of the illuminated target object (Z) or part of the illuminated target object captured by the image acquisition device (3) is analyzed and compared with at least one image of the illuminated target object (Z) or part of the illuminated target object generated at a previous time or with an image stored in an object database; that based on this comparison, a correction signal (K) is determined, which is applied to an optical correction device (12) arranged in the optical path (P) traversed jointly by the high-energy laser beam (L) and the reflected radiation (B'); that the result of the comparison carried out in the image processing device (34) is fed to a filter device (38) and, in parallel, to a fine-tracking controller (39);that a filter correction signal (KF) is generated by the filter device (38) and a controller correction signal (KR) is generated by the fine-tracking controller, and that the correction signal (K) is formed from the filter correction signal (KF) and the controller correction signal (KR).