Shaped-Aperture Scanning Cameras for Oblique Multi-View Imaging
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Solution Overview
Problem
Scanning designs in high-altitude aerial imaging systems are not optimized for oblique imaging or multi-view imaging, limiting the efficiency and effectiveness of capturing high-resolution images of large areas.
Innovation Solution
A scanning camera system with dynamically shaped apertures and tilted scanning mirrors that allow for capturing images along curved scan paths, incorporating multiple camera assemblies with varied viewing angles and directions, and using correction mirrors to bend optical axes, enabling oblique and nadir imaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional scanning design with a rotating mirror is used for high-altitude wide-area imaging, then large areas can be imaged efficiently, but the system is not optimized for oblique imaging or multi-view imaging
Solution Approach 1:
The patent employs a dynamically shaped aperture that changes its geometry (from circular to elliptical to linear) as the scanning mirror rotates through different angles. This dynamic adaptation allows the system to optimize the imaging beam shape for different scan positions, enabling effective oblique and multi-view imaging while using a single rotating mirror mechanism rather than multiple fixed mirrors for different viewing angles
2Area of moving object
If the scanning mirror size is reduced to minimize system size, then the device becomes more compact, but the imaging beam may be clipped by the mirror edges
Solution Approach 1:
The dynamically shaped aperture adapts its shape and size to match the required beam footprint at different scan angles. When the scan angle changes, the aperture transforms from a larger circular shape to a more focused elliptical or linear shape, ensuring the imaging beam is properly contained and directed onto the scanning mirror without clipping, while allowing the mirror itself to remain compact
Solution Approach 2:
The system changes the aperture parameters (shape, size, orientation) as a function of the spin angle. This parameter adaptation ensures that the aperture always provides the optimal opening shape for the current beam direction, preventing beam clipping while minimizing the required scanning mirror size
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 imaging efficiency by minimizing scanning mirror size, allowing for high-resolution multi-view imaging with oblique and nadir views, facilitating accurate 3D surface reconstruction and orthomosaic generation.
Implementation Method 1
The scanning mirror is tilted relative to the camera optical axis and is positioned to reflect an imaging beam into the lens
Implementation Method 2
Each lens is positioned to focus the imaging beam onto its respective image sensor
Data Source
AI summary
A scanning camera includes a camera assembly associated with curved scan paths. Each camera assembly includes an image sensor and a lens, and has a camera optical axis. Also included are a scanning mirror, and a drive to rotate the scanning mirror about a spin axis, which is tilted relative to the camera optical axis, according to a spin angle. The scanning mirror is tilted relative to the spin axis. For each camera assembly, the scanning mirror is tilted relative to the camera optical axis, and is positioned to reflect an imaging beam into the lens. A viewing angle and a viewing direction of the imaging beam relative to the object plane varies with the spin angle and a pointing direction of the camera optical axis. Each lens focuses the imaging beam onto its respective image sensor, which captures each image along a respective scan path.