Aircraft Position Measurement Using Satellite Reflector Ranging

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Solution Overview

Problem

Current aircraft position measurement techniques, such as GPS and celestial navigation, are vulnerable to signal jamming and spoofing, and celestial navigation involves high computational loads and limited daytime use, making them unreliable for accurate position determination without external signals.

Innovation Solution

An aircraft position measurement system utilizing an artificial satellite in a known orbit, equipped with a reflector and a laser distance-angle measuring device, calculates the aircraft's position based on the satellite's absolute position and measured bearing and distance, reducing reliance on external signals and improving accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If GPS is used for aircraft position measurement, then position determination is simplified, but the system becomes vulnerable to signal jamming and spoofing

Engineering Contradiction:

Improveposition determinationVSAvoidsignal security

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent introduces a passive reflector on the satellite as an intermediary element. Instead of directly receiving signals from the satellite (which can be jammed or spoofed), the aircraft measures the reflection of its own electromagnetic wave off the passive reflector. This intermediary reflection mechanism provides a trusted, passive target that cannot be easily spoofed, resolving the security vulnerability while maintaining operational simplicity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If celestial navigation is used for aircraft position measurement, then external signal dependency is reduced, but computational load increases and daytime use is limited

Engineering Contradiction:

Improveexternal signal independenceVSAvoidcomputational load

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex computational celestial navigation algorithms with a simpler electromagnetic wave reflection measurement system. Instead of calculating positions based on celestial body observations requiring heavy computation, the system uses direct electromagnetic wave transmission and reflection measurement, significantly reducing computational load while maintaining external signal independence.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

Instead of the aircraft actively receiving signals from satellites (traditional approach), the system inverts the approach by having the aircraft emit electromagnetic waves and measure their reflection from the satellite's passive reflector. This inversion eliminates the need for complex signal processing and celestial body tracking algorithms, reducing computational complexity while achieving the same position determination goal.

Inventive Principle:

Principle #13The other way round (Inversion)

3Use of energy by moving object

If active satellites are used for position measurement, then signal strength is sufficient, but the system requires complex onboard receivers and is vulnerable to jamming

Engineering Contradiction:

Improvesignal strengthVSAvoidreceiver complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The passive reflector acts as an intermediary that enables the aircraft to measure satellite position using its own transmitted electromagnetic waves. The reflector returns the transmitted signal to the aircraft, allowing the use of simpler onboard equipment while maintaining sufficient signal strength for accurate measurement, and eliminating vulnerability to jamming since the reflector is passive and cannot be controlled by adversaries.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 system enables reliable and accurate aircraft position measurement even when GPS signals are compromised, with reduced computational load and no daytime limitations, ensuring precise positioning at high altitudes.

Implementation Method 1

a reflector configured to be mounted on the artificial satellite and reflect an electromagnetic wave in a direction in which the electromagnetic wave arrives

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS11132905B2Aircraft position measurement system, aircraft position measurement method, and aircraft

Publication Date: 2021.09.28 SUBARU CORP

AI summary

An aircraft position measurement system is provided for an aircraft configured to use an artificial satellite configured to fly in a known orbit. The aircraft position measurement system includes a reflector, a distance-angle measuring member, a satellite position obtainer, and an aircraft position calculator. The reflector configured to be mounted on the artificial satellite and reflect an electromagnetic wave in a direction in which the electromagnetic wave arrives. The distance-angle measuring member is configured to be mounted on the aircraft and emit an electromagnetic wave and measure a bearing and a distance to the artificial satellite when seen from the aircraft. The satellite position obtainer is configured to obtain an absolute position of the artificial satellite. The aircraft position calculator is configured to calculate a position of the aircraft based on the absolute position of the artificial satellite and the bearing and the distance to the artificial satellite.