A Simplified Solution Separation Method for GNSS Fault Detection in Challenging Environments
Résumé
Providing a reliable position solution is essential for many safety-critical and reliability-critical location-based services. However, the Global Navigation Satellite System (GNSS) has inherent vulnerability and satellite signals are prone to be disturbed by surrounding obstacles, leading to misleading solutions. The Solution Separation (SS) detector can cope with various fault conditions but its associated subset number is large, making the implementation process complex. To address this, a simplified solution separation method is proposed in this paper. To reduce the computational complexity, the relationship between the full set solution and the subset solution is derived in detail to avoid recalculating the subset solution from scratch. Meanwhile, a new multiple-fault exclusion scheme with fewer subsets is designed based on the above relation formula. A simulated experimental platform is built, where single and double GNSS faults are injected into the raw observations with various amplitudes. The test statistic variation is analyzed and all injected faults are excluded successfully. The position error comparison further validates the effectiveness of the proposed method.