Inertial Coasting Position And Velocity Separation for GPS Spoofing Detection
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Solution Overview
Problem
Existing inertial navigation systems struggle to detect bias errors in aiding sources like GPS, which can corrupt the navigation solution over time, making it difficult to distinguish between legitimate and erroneous measurements.
Innovation Solution
An inertial coasting monitoring system with multiple non-GNSS aided inertial coast sub-filters is employed to detect faults in aiding data by comparing position and velocity discriminators against thresholds, allowing for early detection of GPS threat events such as spoofing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If residual measurement screening is used for failure detection, then large and obvious failures can be detected, but bias errors cannot be detected early
Solution Approach 1:
The navigation filter is segmented into multiple parallel filters (primary filter and multiple secondary filters). Each filter processes aiding measurements independently, allowing comparison of results to detect bias errors. The secondary filters use different measurement combinations or processing methods, creating diverse solutions that can identify corrupted measurements through discrepancy analysis.
Solution Approach 2:
An intermediary fault detection mechanism is introduced that compares the primary filter solution with secondary filter solutions. This intermediary comparison layer acts as a mediator to identify bias errors before they corrupt the navigation solution, enabling early detection of GPS spoofing and other measurement corruptions.
2Measurement precision
If aided inertial navigation is used to improve accuracy, then navigation precision is enhanced, but susceptibility to aiding source corruption increases
Solution Approach 1:
The navigation system is divided into multiple parallel filter paths (primary and secondary filters) that process GPS aiding measurements independently. By segmenting the measurement processing, the system can compare results across filters to identify corrupted measurements, thereby maintaining accuracy while reducing vulnerability to GPS spoofing attacks.
Solution Approach 2:
The secondary filters perform preliminary processing of GPS measurements to establish baseline solutions before the primary filter incorporates potentially corrupted measurements. This preliminary action allows the system to detect anomalies in advance and prevent corrupted data from degrading navigation accuracy.
3Reliability
If multiple inertial coast sub-filters are implemented for fault detection, then detection capability is improved, but system complexity increases
Solution Approach 1:
The filter system is segmented into a hierarchical structure with one primary filter and multiple secondary filters, each handling specific measurement combinations. This segmentation enables sophisticated fault detection through comparison while organizing complexity in a manageable hierarchical manner, reducing the computational burden compared to fully parallel complex filter networks.
Solution Approach 2:
Different secondary filters are designed with local quality variations, each specializing in detecting specific types of faults or processing specific measurement combinations. This localized specialization allows the system to achieve comprehensive fault detection capability while keeping individual filter designs relatively simple and computationally efficient.
Data Source
AI summary
An inertial coasting monitoring system comprises aiding sensors onboard a vehicle, including a GNSS receiver and at least one non-GNSS aiding sensor, and an inertial measurement unit (IMU) that produces inertial measurements for the vehicle. A navigation system is coupled to the aiding sensors and the IMU. The navigation system comprises a main navigation filter and an inertial navigation system (INS). The navigation filter receives aiding data from the aiding sensors including GNSS aided data, and the INS receives inertial data from the IMU. An onboard inertial coasting monitor communicates with the navigation system, and receives inertial data from the IMU and aiding data from at least one non-GNSS aiding sensor. The inertial coasting monitor comprises inertial coast sub-filters and communicates with the navigation filter. The inertial coasting monitor performs a position detection process and/or a velocity detection process to detect if there is a fault in the aiding data.