LEO Satellite IR Light Source for Celestial Navigation Visibility
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Solution Overview
Problem
Current celestial navigation systems face operational limitations due to limited satellite visibility during the day and around midnight, as satellites are difficult to observe due to background sunlight and Earth's shadow.
Innovation Solution
Equipping low earth orbit (LEO) satellites with infrared (IR) light source emitters, allowing for direct observation by a star tracker during nighttime and using bandpass filters to observe IR light during daytime, thereby overcoming visibility issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If celestial navigation uses reflected visible light from satellites, then satellites are observable at terminator conditions (near sunrise and sunset), but operation during daytime is difficult due to background sunlight and operation near midnight is impossible due to Earth's shadow
Solution Approach 1:
The patent changes the light source parameter from reflected visible light to active infrared light emission. Satellites equipped with infrared light sources can be observed continuously regardless of sunlight conditions or Earth's shadow, eliminating the terminator condition limitation and enabling operation during daytime and midnight periods when reflected light navigation fails
Solution Approach 2:
The patent introduces an intermediary infrared light source on satellites that mediates the observation problem. This active light source enables the star tracker to detect satellites independently of solar illumination, serving as a reliable intermediary signal that overcomes the harmful effect of background sunlight and Earth's shadow
2Use of energy by moving object
If satellites rely on reflected visible light for observation, then no additional power is required on satellites, but observation is limited to specific times and conditions
Solution Approach 1:
The patent changes the energy parameter by introducing active infrared light sources on satellites. Although this requires additional power consumption on satellites, it provides continuous observability during daytime and midnight periods, significantly improving navigation availability and reliability to overcome the limitations of reflected light methods
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 celestial navigation by enabling continuous nighttime tracking and improving daytime tracking, resulting in more reliable and accurate navigation with reduced error and increased availability.
Implementation Method 1
Equipping low earth orbit (LEO) satellites with infrared (IR) light source emitters, allowing for direct observation by a star tracker during nighttime
Implementation Method 2
using bandpass filters to observe IR light during daytime, thereby overcoming visibility issues
Data Source
AI summary
A method and system for celestial navigation are provided. The method comprises requesting access to a light source on a low earth orbit (LEO) satellite; and sending an uplink message to the LEO satellite to power on the light source, in response to the access request. The method further comprises determining whether the LEO satellite is in view of a camera; capturing a light image, from the light source, on a focal plane location of the camera when the LEO satellite is in view of the camera; and comparing the focal plane location to a predicted location of the LEO satellite. The method updates position information of a user based on an observation error from comparing the focal plane location to the predicted location.