Airborne Imaging Survey Platform Using Curved-Projection Sensor Arcs
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Solution Overview
Problem
Existing imaging survey platforms face challenges in achieving a very wide field of view and high magnification due to limitations in focal length, aperture size, and optical resolution, particularly when capturing imagery from high altitudes, leading to restricted survey rates and resolution.
Innovation Solution
The arrangement of imaging sensors in arcs with a primary lens subsystem projecting onto a curved surface, combined with optional secondary arcs or scanning mirrors, allows for high-speed data capture and correction of optical distortions using piezoelectric actuators and image relay lenses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If focal length is increased to achieve higher magnification and resolution from high altitude, then Ground Sampling Distance (GSD) resolution is improved, but the physical size and mass of the lens system increases, making it difficult to package and rotate
Solution Approach 1:
The imaging system is divided into multiple independent camera modules, each with its own lens and sensor. Instead of using one large complex lens system, the patent employs several smaller lens-camera assemblies that can be independently positioned and oriented to capture different viewing angles simultaneously.
Solution Approach 2:
The patent transitions from a single viewpoint to multiple viewpoints by arranging camera modules in three-dimensional space around the platform. This spatial distribution across multiple dimensions allows the system to achieve wide field of view and high resolution without requiring an excessively large focal length in any single lens.
2Illumination intensity
If scanning mirror size is increased to provide more light for longer focal length systems, then illumination intensity is improved, but the mass of the mirror increases, making it harder to move and stop quickly without introducing vibrations
Solution Approach 1:
Instead of using one large scanning mirror, the patent divides the light collection function across multiple smaller camera modules, each with its own smaller lens and sensor assembly. This eliminates the need for a large scanning mirror while still providing sufficient light to each sensor.
Solution Approach 2:
The patent replaces the mechanical scanning mirror system with a static multi-camera array that captures multiple viewing angles simultaneously. This eliminates the moving mirror mechanism entirely, removing the source of vibrations while maintaining light collection efficiency.
3Productivity
If the number of frames per second captured by a single sensor is increased to improve survey rate, then productivity is improved, but the limit on frame rate restricts the capability of scanning mirror or moving camera systems
Solution Approach 1:
The patent divides the total imaging task across multiple independent camera modules, each capturing images at moderate frame rates. By parallelizing the capture across several sensors simultaneously viewing different angles, the system achieves high effective survey rates without requiring any single sensor to operate at extreme frame rates.
4Area of stationary object
If a wide field of view of at least 90 degrees is achieved in one axis, then the area captured per hour is improved, but the combination of wide angle lens and telephoto lens requirements creates optical design challenges
Solution Approach 1:
Instead of attempting to design a single optical system that provides both wide field of view and high magnification, the patent segments the function across multiple camera modules. Each module uses a standard lens design optimized for its specific viewing angle, avoiding the need for complex multi-functional optics.
Solution Approach 2:
The patent achieves wide field of view not through a single wide-angle lens but by distributing multiple standard-lens cameras across three-dimensional space. The collective field of view of the array provides the wide coverage without requiring any individual lens to be a complex wide-angle design.
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 configuration enables high-resolution imaging of large areas at rates up to 10,000 km² per hour with 5 cm GSD, capturing multiple oblique views, significantly surpassing current systems in both resolution and survey speed.
Implementation Method 1
correction of optical distortions using piezoelectric actuators
Data Source
AI summary
An imaging survey platform utilizes imaging sensors arranged in one or more arcs to capture nadir and oblique views as required for photogrammetric processing into image maps and 3D surface maps, where a common primary lens subsystem is used by sensors within an arc. The primary lens subsystem can project onto a curved (e.g., spherical) surface rather than onto a planar surface. This solves a limiting first order optical problem for airborne or spaceborne image capture. To fill missing data between sensors edges on an arc, a second and offset arc of sensors or a scanning mirror in front of the primary mirror system can be used. Each imaging sensor can be mounted on and controlled by its own computer, with this subsystem in turn may be mounted onto the arc using piezoelectric actuators to fine tune alignment image sensor relative to the primary lens subsystem.