GNSS Spoofing Detection via Geometric Signal Block Analysis
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Solution Overview
Problem
Existing navigation systems are vulnerable to multiple corrupted GNSS signals, such as spoofing, which can lead to incorrect navigation data and pose safety risks, especially for aircraft.
Innovation Solution
A system and method using a single antenna and a processor to detect multiple spoofed or faulty GNSS signals by determining unit vectors, signal blocks, and comparing geometry in local coordinates with satellite coordinates, employing a balanced incomplete block design (BIBD) to efficiently identify corrupted signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional RAIM methods are used to detect faulty GNSS signals, then single satellite signal integrity can be monitored, but the system cannot detect multiple spoofed or faulty signals from multiple satellites
Solution Approach 1:
The patent divides the set of all satellite signals into multiple signal blocks, where each block contains a subset of signals. By applying BIBD, the segmentation ensures that every possible pair of spoofed signals appears together in exactly λ blocks, allowing the system to detect multiple faulty signals through geometric comparison across different blocks rather than treating all signals as a single group.
Solution Approach 2:
The patent introduces a geometric dimension by determining unit vectors in local coordinates for each satellite and comparing the geometry of local coordinates with satellite coordinates. This geometric comparison across multiple signal blocks enables detection of spoofed signals by identifying inconsistencies in the spatial relationships, adding a dimensional aspect to the detection process beyond simple signal intensity or timing analysis.
2Reliability
If comprehensive signal verification methods are implemented to detect multiple spoofed signals, then navigation integrity improves, but computational complexity and processing requirements increase significantly
Solution Approach 1:
Instead of verifying all possible combinations of satellite signals (which would be excessive), the patent uses BIBD to select a specific subset of signal blocks that provides optimal detection coverage. The BIBD parameters ensure that every pair of spoofed signals is covered exactly λ times, providing sufficient detection capability with fewer blocks than a complete enumeration would require, thus reducing computational complexity while maintaining detection accuracy.
3Productivity
If multiple signal blocks are analyzed using BIBD to detect spoofed signals, then detection efficiency improves with fewer sub-sub-filters, but the mathematical complexity of implementing BIBD increases
Solution Approach 1:
The patent pre-establishes the BIBD structure and signal block configurations before actual signal detection begins. The unit vectors and signal block assignments are determined in advance based on satellite geometry and BIBD parameters, so that during operation, the system only needs to perform comparisons within the pre-defined blocks rather than dynamically calculating all possible combinations, thereby improving real-time detection efficiency.
Data Source
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AI summary
A system and method for detecting multiple spoofed or faulty global navigation satellite signals are provided. The system comprises a single antenna configured to receive satellite signals from a plurality of global navigation satellites, the single antenna located on a vehicle; a receiver in the vehicle, the receiver coupled to the single antenna; and at least one processor in the vehicle, the processor in communication with the single antenna through the receiver. The processor is operative to determine a unit vector in a direction from the vehicle to a global navigation satellite in local coordinates, from the satellite signals; determine a plurality of signal blocks, wherein the signal blocks are a collection of subsets of the satellite signals and a covariance matrix for the satellite signals; and determine which satellite signals in the signal blocks are spoofed or faulty by comparing a geometry of the local coordinates with satellite coordinates.