Vertical Navigation System Using Star Trackers and Gravity

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Solution Overview

Problem

Satellite navigation systems are susceptible to service disruptions due to interference, making them unreliable in critical situations, and there is a need for a navigation system that can operate independently of GPS while providing accurate geolocation in defense and emergency applications.

Innovation Solution

A vertical navigation system that generates aligned geographic coordinates using a source beam, gravity vector measurements, and sensor coordinates from a background star field, combining these with a time signal to determine the vertical position, which can operate without active transmissions and is suitable for GPS-denied environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If satellite navigation systems are used for position determination, then global coverage and position accuracy of a few meters are achieved, but service availability is degraded due to susceptibility to interference and intentional jamming

Engineering Contradiction:

Improveservice availabilityVSAvoidinterference susceptibility

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the navigation function from dependence on satellite signals by implementing a self-contained optical navigation system that uses star trackers and inertial sensors to determine position independently of GPS infrastructure, thereby eliminating susceptibility to radio frequency interference and jamming

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces optical sensors (star trackers) and inertial measurement units as intermediary systems that mediate between the vehicle and the navigation function, allowing position determination through optical celestial reference rather than electromagnetic satellite signals

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If passive high-accuracy navigation systems are used in GPS-denied environments, then covertness and resistance to GPS denial are maintained, but the technology is subject to export restrictions as sensitive defense technology

Engineering Contradiction:

Improveoperation in GPS-denied environmentsVSAvoidexportability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent designs a navigation system with dual applicability that can function both as a passive optical navigation system for defense applications and as an active illumination system for civilian surveying and mapping, allowing the same hardware platform to serve multiple purposes and potentially bypass export restrictions through commercial applications

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Measurement precision

If active navigation signals are transmitted for position determination, then position accuracy is achieved, but signal/noise ratio is low making the system susceptible to service disruption

Engineering Contradiction:

Improveposition accuracyVSAvoidservice disruption susceptibility

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent inverts the traditional active satellite-to-receiver signal transmission model by using passive reception of celestial optical signals combined with active inertial measurement, creating a navigation system that determines position through local sensing rather than remote signal reception, thereby eliminating low signal/noise ratio problems

Inventive Principle:

Principle #13The other way round (Inversion)

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 provides accurate and independent navigation, maintaining operational secrecy and high accuracy, even in GPS-denied environments, making it suitable for defense and emergency applications.

Implementation Method 1

a retroreflector to reflect the laser beam

Methodology Applied

Scientific EffectRetroreflection: Retroreflector

Implementation Method 2

a gravity sensor to measure a gravity vector

Methodology Applied

Scientific EffectGravitation: Gravitation

Implementation Method 3

a star tracker to measure sensor coordinates of stars and the vertical references

Methodology Applied

Scientific EffectStellar parallax and celestial reference: Parallax

Data Source

PatentUS11841230B2Vertical navigation system

Publication Date: 2023.12.12 HUTCHIN RICHARD A

AI summary

Aspects of the disclosure are directed to acquiring aligned geographic coordinates of a vertical position. In one aspect, a vertical navigation system includes a light source to generate a source beam; a beam splitter to generate a first and a second source references derived from the source beam; a hollow retroreflector to produce a first and a second vertical references derived from the first and the second source references; an attitude sensor to capture a plurality of reference stars and to measure a first set of angles for the first vertical reference and a second set of angles for the second vertical reference, the first set of angles and the second set of angles are relative to the plurality of reference stars; and a processor to produce the aligned geographical coordinates using the first set of angles, the second set of angles, a gravity vector measurement and a time signal.