Polarization Optical Compass Sun Elevation Navigation
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Solution Overview
Problem
Conventional navigation methods relying on GPS are unreliable in certain locations or situations, and existing optical compasses that do not rely on GPS are expensive.
Innovation Solution
A polarization optical compass that utilizes the polarization characteristics of electromagnetic radiation from the sun to determine the sun's elevation and azimuth, employing a polarizing filter assembly and sensor system to generate data for a processor device, which calculates the sun's position without GPS.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If GPS is used for navigation, then navigation accuracy is improved, but GPS may not be available in certain locations or situations
Solution Approach 1:
The patent uses the sun as an intermediary reference object for navigation when GPS is unavailable. By measuring the sun's position and polarization characteristics, the system provides an alternative navigation method that works independently of GPS satellite signals, thus resolving the contradiction between navigation availability and GPS coverage limitations.
Solution Approach 2:
The system uses naturally occurring sunlight and its polarization properties as a free, always-available reference for navigation. This self-service approach eliminates dependency on external GPS infrastructure, enabling navigation in locations where GPS signals are blocked or unavailable.
2Reliability
If conventional optical compasses are used that do not rely on GPS, then navigation is possible without GPS, but the cost is high
Solution Approach 1:
The patent employs inexpensive polarizing filters and standard image sensors instead of expensive specialized optical components. By using commercially available, low-cost components that can be mass-produced, the system achieves GPS-independent navigation capability at a fraction of the cost of conventional optical compasses.
Solution Approach 2:
The patent replaces complex mechanical optical compass mechanisms with an electronic imaging-based system. By using digital image processing and computational algorithms to analyze polarized light patterns from the sun, the system eliminates expensive mechanical components while maintaining navigation accuracy.
3Measurement precision
If polarization filtering is used to determine sun position, then navigation accuracy is improved, but device complexity increases
Solution Approach 1:
The patent divides the optical system into multiple discrete polarizing filters with different orientation angles. Each filter captures polarization information at specific angles, and the processor combines these segmented measurements to calculate the sun's position. This segmentation approach improves measurement precision while keeping individual filter elements simple and manageable.
Solution Approach 2:
The patent adds the polarization angle dimension to the traditional two-dimensional image capture. By incorporating polarizing filters that measure light intensity at different polarization orientations, the system extracts additional information about the sun's position without requiring complex mechanical movements or multi-axis sensors.
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
Provides a cost-effective and reliable method for determining direction using the sun's polarization characteristics, enabling navigation in GPS-unavailable areas.
Implementation Method 1
The at least one polarizing filter assembly is configured to receive electromagnetic radiation (EMR) emitted by a sun and transmit, by the at least one polarizing filter assembly, at least three different portions of EMR towards the at least one sensor, each portion filtered based on a different polarization orientation
Implementation Method 2
The at least one sensor comprising a grid of a plurality of detector elements. The processor device is configured to receive sensor data generated by the at least one sensor in response to receipt of the at least three different portions of EMR
Data Source
AI summary
An optical assembly that includes at least one polarizing filter assembly and at least one sensor. The polarizing filter assembly is configured to receive electromagnetic radiation (EMR) emitted by a sun and transmit at least three different portions of EMR towards the at least one sensor, each portion filtered based on a different polarization orientation. A processor device is configured to receive sensor data generated by the at least one sensor in response to receipt of the at least three different portions of EMR, and determine an elevation angle of the sun with respect to a horizon from a geographic location of the optical assembly.