Laser Radar Beam Anisotropy Control for Scanning Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current laser radar systems require multiple scans to achieve high sensitivity, especially at varying distances, which can be inefficient and may compromise signal-to-noise ratio.
Innovation Solution
A laser radar system with a beam that increases its anisotropy as the elevation angle deviates from the horizontal, maintaining constant beam width while adjusting beam height, allowing for higher sensitivity at longer distances and reducing the number of scans needed for shorter distances, using a diverging beam with selectable divergence in the elevation direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a narrow beam is used for detecting targets, then measurement precision is improved, but the field of view is limited and multiple scans are required
Solution Approach 1:
The patent applies dynamics by making the beam width adjustable rather than fixed. The beam width is dynamically adapted based on the azimuth angle: narrow at small angles for high precision, and wider at large angles to cover more area, thereby resolving the contradiction between measurement precision and scanning speed
Solution Approach 2:
The patent changes the beam width parameter as a function of azimuth angle. By varying this physical parameter dynamically, the system achieves high angular resolution when needed while maintaining high scanning efficiency, directly addressing the contradiction between precision and productivity
2Productivity
If the beam width is increased to cover larger areas, then productivity is improved, but measurement precision deteriorates
Solution Approach 1:
The patent applies local quality by making different parts of the angular space have different beam widths. Small azimuth angles receive narrow beams for high precision, while large azimuth angles receive wide beams for high coverage. This local adaptation resolves the contradiction between productivity and measurement precision
3Productivity
If multiple beams are used to cover different directions, then productivity is improved, but device complexity increases
Solution Approach 1:
The patent uses a single beam whose width is dynamically adjusted rather than multiple fixed beams. This dynamic approach achieves the same coverage as multiple beams but with simpler device architecture, resolving the contradiction between productivity and device complexity
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 enhances sensitivity at longer distances while minimizing the number of scans required, improving efficiency and maintaining a strong signal-to-noise ratio by compensating for distance variations in beam intensity distribution.
Implementation Method 1
A laser beam is transmitted from the radar and reflected light is detected
Implementation Method 2
The beam forming optics is configured to form an anisotropic cross section of the beam in directions transverse to the beam axis, with a first dimension in an elevation direction and a second dimension in an azimuth direction
Data Source
Figure 1~1a
Figure 2~3
Figure 4~5
AI summary
A laser radar is provided that comprises a laser beam source arranged to generate a laser beam, means for changing an elevation angle of a beam axis of the beam, means for controllably adjusting anisotropy of a cross- section of the beam and a controller configured to control adjustment of a degree of anisotropy of the beam in correspondence with changes of the elevation angle. The laser radar may be used for example with the beam directed downward at grazing angles to a surface, the controller being configured to increase the degree of anisotropy with increasing angle to a direction of the surface. In this case, elevation angle corresponds to distance to the target. By adjusting anisotropy with distance, higher sensitivity can be realized at long distance and less scans are required to cover shorter distances. A beam with a diverging profile may be used, which diverges anisotropically, with selectable divergence in the elevation direction and constant divergence perpendicularly to the elevation direction. This may be realized using movable or rotatable cylindrical lenses, reflectors or refracting optical elements.