GNSS Spoofing Detection via Terrain Height Comparison
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Solution Overview
Problem
GNSS receivers are susceptible to spoofing attacks, which can lead to incorrect determination of location and time, posing a significant risk to vehicles and their occupants, as they may result in accidents such as incorrect landing trajectories for aircraft.
Innovation Solution
A GNSS spoofing detection system that uses a combination of GNSS receivers and independent height above terrain circuitry, such as radar altimeters, to determine vehicle height and compare it with calculated height from terrain databases, triggering alerts and switching to alternative position data sources when spoofing is detected, thereby ensuring safer navigation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GNSS receiver is used for position determination, then fast and accurate position information is obtained, but the system becomes susceptible to spoofing attacks causing incorrect location and time determination
Solution Approach 1:
The patent introduces an intermediary verification system that compares GNSS-derived height with terrain database height. This intermediary check acts as a mediator to detect spoofing attempts without replacing the GNSS receiver, thereby maintaining measurement precision while improving reliability through cross-validation with independent terrain data
Solution Approach 2:
The system implements feedback by continuously monitoring the difference between determined and calculated heights, and using this information to trigger alerts or switch to alternative position data sources when spoofing is detected, creating a closed-loop verification mechanism that enhances system reliability
2Reliability
If alternative position data sources are used when spoofing is detected, then navigation safety is improved, but system complexity increases due to multiple data sources and switching mechanisms
Solution Approach 1:
The system employs self-service by using the terrain database (which is independently available) to verify GNSS data integrity. The verification process is automatically performed by the same system that uses the GNSS data, reducing the need for external verification systems and minimizing additional complexity while maintaining navigation safety
Solution Approach 2:
The patent applies partial verification by focusing only on the height component for spoofing detection rather than verifying all position parameters. This selective approach provides sufficient safety improvement while avoiding the complexity of comprehensive multi-parameter verification systems
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 effectively detects GNSS spoofing by comparing determined and calculated vehicle heights, alerting users and switching to alternative position data sources, thereby enhancing the reliability of navigation systems and reducing the risk of accidents.
Implementation Method 1
independent height above terrain circuitry, such as radar altimeters
Data Source
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AI summary
A system comprises processing circuitry configured to receive position data from a global navigation satellite system (GNSS) receiver and to receive a first vehicle height above terrain (HAT) from HAT circuitry. A lateral position and an altitude are derived from the position data. The processing circuitry is further configured to determine terrain elevation based upon the lateral position. The processing circuitry is further configured to determine a second vehicle height above terrain (HAT) based upon subtracting the determined terrain elevation from the altitude. The processing circuitry is further configured to detect GNSS spoofing based upon a difference between the first vehicle HAT and the second vehicle HAT; and upon detecting GNSS spoofing, issue an alert.