GNSS Spoofing Detection Using Independent Bearing and Range Sensors
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Solution Overview
Problem
GNSS spoofing poses a significant risk to vehicle navigation systems, particularly in aircraft, as it can lead to incorrect position information, potentially causing crashes and other safety hazards, and existing detection methods are inadequate.
Innovation Solution
A method using independent sensors such as VOR, DME, radar, and lidar to verify GNSS position solutions by comparing measured bearing and range data with expected values, employing analytical algorithms like RAIM to detect spoofing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GNSS technology is used for navigation, then position determination speed and accuracy are improved, but the system becomes vulnerable to spoofing attacks that can lead to incorrect position information
Solution Approach 1:
The patent introduces an intermediary verification system that uses independent sensors (barometer, magnetometer, accelerometer, GPS velocity) to mediate between the potentially spoofed GNSS position data and the navigation system. This intermediary layer cross-checks the GNSS position against measurements from these independent sensors to detect and reject spoofed signals, thus resolving the contradiction between using GNSS for accurate positioning and protecting against spoofing attacks.
2Reliability
If multiple independent sensors are added to verify GNSS position, then spoofing detection capability is improved, but device complexity increases
Solution Approach 1:
The patent employs sensors that serve multiple functions: the barometer provides both altitude measurement and spoofing detection data; the magnetometer contributes to position verification and can detect magnetic anomalies; the accelerometer provides velocity information for cross-validation. By selecting sensors with multi-functional capabilities, the system achieves robust spoofing detection while minimizing the increase in device complexity.
Solution Approach 2:
The verification system uses the vehicle's existing sensor suite and navigation data for cross-checking GNSS position, rather than requiring entirely separate dedicated verification equipment. The system leverages data already being collected for other navigation purposes (velocity from accelerometers, altitude from barometers) to perform spoofing detection, thereby reducing overall system complexity.
3Reliability
If real-time spoofing detection is implemented, then safety and reliability are improved, but processing time and computational load increase
Solution Approach 1:
The patent implements a tiered verification approach where the system performs quick partial checks using readily available sensor data (barometric altitude, magnetometer readings) that can be processed rapidly. More comprehensive verification using multiple sensors and complex algorithms is performed only when initial checks indicate potential spoofing or when the vehicle is in high-risk environments. This partial action approach maintains real-time detection capability while reducing average processing time.
Data Source
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AI summary
Improvements in Global Navigation Satellite System (GNSS) spoofing detection of a vehicle are disclosed utilizing bearing and/or range measurements acquired independently from GNSS technology. Bearing and/or range measurements are determined from a GNSS-calculated position. Additionally, bearing and/or range measurements are acquired from an independent sensor, such as a Very high frequency Omnidirectional Range (VOR) receiver and/or a Distance Measurement Equipment (DME) receiver. The differences between the GNSS-based bearing and/or range and the bearing and/or range determined from the independent sensor, along with any applicable sources of error or uncertainty (including the post-hoc residuals from the GNSS-calculated position), are input into an analytical algorithm (e.g., RAIM) to determine whether GNSS spoofing is present with respect to the calculated GNSS position. If spoofing is detected, an alternative position determining system can be used in lieu of GNSS technology, and alerts can be sent notifying appropriate entities of the spoofing result.