Underwater Celestial Beacon for GPS-Free Position Recalibration

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Solution Overview

Problem

Underwater vehicles face challenges in maintaining accurate navigation without direct access to GPS signals, as resurfacing for position updates is impractical and existing seabed beacon systems are costly and non-covert.

Innovation Solution

A stationary underwater celestial navigation beacon that determines its own position using inertial measurement units and gravitational pull of the moon, providing accurate latitude and longitude data without external sensors or visual celestial object access, and communicates this data to other vehicles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If underwater vehicles resurface to access GPS satellites for position updates, then navigation accuracy is improved, but operational continuity and mission secrecy are compromised

Engineering Contradiction:

Improvenavigation accuracyVSAvoidoperational continuity

Core Design Contradiction:

Measurement precisionVSDuration of action of moving object

Solution Approach 1:

The patent introduces seabed beacons as intermediary devices that receive GPS position data from satellites and transmit it to underwater vehicles via acoustic modems. This mediator enables position updates without requiring the underwater vehicle to resurface, thus maintaining navigation accuracy while preserving operational continuity and mission secrecy.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical/physical requirement of surfacing to access GPS signals with an acoustic communication system. Underwater vehicles receive position data through acoustic modems from seabed beacons, substituting the need for physical exposure to air and GPS satellites with an underwater-compatible acoustic transmission medium.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If traditional seabed beacon systems are deployed for underwater navigation, then navigation accuracy is improved, but system cost and deployment complexity increase

Engineering Contradiction:

Improvenavigation accuracyVSAvoiddeployment complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent makes the seabed beacons self-configuring devices that automatically determine their own positions using inertial measurement units and gravitational sensor data. This eliminates the need for complex manual surveying and configuration processes, reducing deployment complexity while maintaining navigation accuracy through precisely positioned beacons.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces complex mechanical surveying equipment and manual positioning procedures with automated electronic systems. Inertial measurement units and gravitational sensors automatically determine beacon positions, substituting labor-intensive field surveying with automated computational methods that reduce both time and expertise requirements for deployment.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If inertial navigation systems are used for extended underwater operations, then operational independence is improved, but positional accuracy degrades over time

Engineering Contradiction:

Improveoperational independenceVSAvoidpositional accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism where underwater vehicles periodically receive position corrections from seabed beacons via acoustic modems. This feedback loop allows the inertial navigation system to maintain operational independence while periodically resetting accumulated position errors, thus preserving both operational independence and positional accuracy over extended periods.

Inventive Principle:

Principle #23Feedback

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 and covert navigation for underwater vehicles by recalibrating their inertial navigation systems, reducing the need for surface access and surveying, and providing long-term positional accuracy.

Implementation Method 1

determining a longitude of the underwater celestial navigation beacon based on a gravitational pull of the moon

Methodology Applied

Scientific EffectGravitational pull: Gravitation

Implementation Method 2

determining a latitude of the underwater celestial navigation beacon using the three-axis rate gyroscopic data

Methodology Applied

Scientific EffectGyroscopic effect: Gyroscope

Data Source

PatentEP3973310B1Underwater celestial navigation beacon

Publication Date: 2026.02.25 RAYTHEON CO

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AI summary

An underwater celestial navigation beacon configured to provide position information is disclosed. The underwater celestial navigation beacon can include a data store configured to store an astronomical model of the moon. The underwater celestial navigation beacon can include an inertial measurement unit (IMU) operable to capture IMU data that includes three-axis acceleration data and three-axis rate gyroscopic data. The underwater celestial navigation beacon can include a controller. The controller can determine a latitude of the underwater celestial navigation beacon using the three-axis rate gyroscopic data. The controller can determine a longitude of the underwater celestial navigation beacon based on a gravitational pull of the moon, using the three-axis acceleration data and the astronomical mode! of the moon. The controller can determine the position information for the underwater celestial navigation beacon based on the latitude and longitude.