GNSS Array-Based Multipath Detection Employing UKF on Manifolds

TL;DR

This paper presents a novel GNSS array-based multipath detection method that uses an Unscented Kalman Filter on manifolds combined with RANSAC to improve positioning accuracy in urban environments.

Contribution

It introduces a real-time attitude estimation approach that fuses GNSS and IMU data with UKF on manifolds and employs RANSAC to efficiently detect multipath-affected satellites.

Findings

Enhanced multipath detection accuracy in urban scenarios

Significant improvement in positioning precision

Effective reduction of computational load with RANSAC

Abstract

Global Navigation Satellite Systems (GNSS) applications are often hindered by various sources of error, with multipath interference being one of the most challenging, particularly in urban environments. In this work, we build on previous research by implementing a GNSS array-based multipath detection algorithm, incorporating real-time attitude estimation for dynamic scenarios. The method fuses GNSS and IMU data using an Unscented Kalman Filter (UKF) on a manifold, enabling continuous attitude tracking. The proposed approach utilizes attitude information from satellite combinations to identify and exclude multipath-affected satellites, improving the accuracy of both positioning and attitude determination. To address computational challenges associated with evaluating large numbers of satellite combinations, we propose the use of the Random Sample Consensus (RANSAC) algorithm, which reduces the number of combinations assessed while maintaining high detection performance. Performance evaluations are conducted using trajectories and IMU readings from the KITTI dataset. GNSS observations are simulated based on ground truth positions and satellite ephemeris. The results demonstrate the effectiveness of the proposed approach in detecting satellites affected by multipath interference. Significant improvements in positioning accuracy are observed, particularly in scenarios where a large portion of the visible satellites are contaminated by severe multipath.