Multi-Drone Decentralized Cooperative Navigation Strategy for GNSS Integrity Monitoring

This paper investigates a cooperative navigation strategy to mitigate GNSS signal integrity corruption. A decentralized navigation solution based on the Extended Kalman Filter has been developed to this aim. It exploits cooperative measurements coming from either visual or ranging sensors, and foresees platforms can exchange information about both their belief state (i.e., navigation state and covariance) and their integrity status, while avoiding sharing GNSS raw data within the formation to reduce the communication burden. The j-slope concept, used to predict filter performance, and defining the optimal formation geometry while accounting for the needs of all the platforms of the formation, is also introduced. The developed solution has been tested using data obtained from both realistic simulations and experimental campaigns. Results demonstrate the developed solution has navigation performance similar to its centralized version, while being more resilient to failures. In addition, integrity monitoring benefits from the innovative concept of integrity status sharing. Experimental campaigns conducted in relevant environments to capture GNSS signal obstruction and multipath effects demonstrate that cooperation highly improves the performance of the navigation solution.