Celestial Navigation with Cloud Mapping and Beam Steering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Celestial navigation systems face challenges in low-altitude environments due to cloud coverage, which obstructs the visibility of space objects necessary for accurate attitude and position determination.
Innovation Solution
A celestial navigation system comprising a star-tracker, a beam director, and an inertial measurement unit, with a control module that generates a cloud map to identify unobstructed space objects, adjusts the beam director to capture light from these objects, and corrects vehicle attitude, velocity, and position using measurements from the star-tracker and inertial sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If celestial navigation is performed at low altitude, then navigation capability is improved for marine and ground vehicles, but cloud coverage obstructs visibility of space objects reducing measurement availability
Solution Approach 1:
The system performs preliminary actions by generating a cloud map before navigation measurements are taken. The cloud map is used to predict cloud positions and identify potential obstructions in advance, allowing the system to plan measurement strategies that avoid cloudy regions and ensure reliable space object observations even at low altitudes.
Solution Approach 2:
The beam director serves as an intermediary device that actively positions and orients the star-tracker toward clear sky regions identified in the cloud map. This intermediary component enables the system to bypass cloud obstructions by mechanically directing the optical sensor toward unobstructed space objects, maintaining measurement availability despite low-altitude cloud coverage.
2Device complexity
If a star-tracker with fixed field of view is used, then device complexity is reduced, but the ability to track space objects amid cloud interference is limited
Solution Approach 1:
The system implements dynamics by making the star-tracker's field of view movable through the beam director. Instead of a fixed field of view, the optical sensor can dynamically reposition and reorient itself to track space objects as they move across the sky or as clouds obstruct the original view, maintaining reliable tracking capability while adding only minimal mechanical complexity.
3Measurement precision
If GPS is used for navigation, then positioning accuracy is improved and cost is reduced, but vulnerability to jamming and spoofing increases
Solution Approach 1:
The celestial navigation system using a star-tracker and beam director serves as an intermediary independent navigation system that does not rely on GPS signals. By directly observing space objects and calculating position from celestial coordinates, the system provides a secure backup that is immune to GPS jamming and spoofing attacks, maintaining positioning accuracy through physical optical measurements rather than vulnerable radio signal reception.
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 accurate navigation in low-altitude environments by overcoming cloud interference, providing improved position, velocity, and attitude determination by identifying and utilizing unobstructed space objects.
Implementation Method 1
The star-tracker has a field of view for capturing light
Implementation Method 2
The beam director is configured to change a direction of the light captured in the field of view of the star-tracker
Implementation Method 3
The inertial measurement unit has a plurality of sensors for measuring an acceleration and a rotation rate of the vehicle
Data Source
AI summary
A celestial navigation system and method for determining a position of a vehicle. The system includes a star-tracker, a beam director, an inertial measurement unit, and a control module. The star-tracker has a field of view for capturing light. The beam director is configured to change a direction of the light captured in the field of view of the star-tracker. The inertial measurement unit has a plurality of sensors for measuring an acceleration and a rotation rate of the vehicle. The control module executes instructions to correct the attitude, the velocity and the position of the vehicle using the determined magnitude and position of the space objects. The control module also executes instructions to generate corrections to the IMU error parameters, the beam director and star-tracker alignment errors, and RSO ephemeris errors to achieve optimal performance.