Operations that require all or part of a mission to be conducted without access to GNSS data are becoming increasingly common. In certain situations, the GNSS signal might encounter disruptions, or the mission may require that the flight be initiated without a GNSS signal from the onset.
UAV Navigation-Grupo Oesía's Flight Control Solutions are designed from the ground up to operate in GNSS-denied environments. While the flight control system can safely maintain aircraft control and navigate in dead-reckoning mode during GNSS outages, prolonged operations without external position updates inevitably lead to accumulated navigation drift. This is where the Visual Navigation System (VNS01) provides a critical advantage, delivering absolute position corrections that constrain drift and maintain precise navigation when GNSS signals are unavailable, unreliable or compromised.
When integrated with the VECTOR flight control systems, the VNS01 reduces inertial drift and delivers more accurate positioning than the MEMS-based inertial navigation systems typically used on this class of aircraft due to size, weight, and power constraints.
The VNS01 processes data from its onboard camera and other sensors to estimate motion and absolute position relative to the environment below, reducing inertial drift over extended periods. In previously surveyed areas, the system can use imagery collected from previous flights as a navigation reference, applying pattern recognition to continuously correct positioning errors and reduce the drift to near-zero levels. In areas that were previously not flown, it can rely on preloaded satellite imagery correlating features captured by the onboard camera. It can also rely on preloaded satellite imagery correlating features captured by the onboard camera.
In addition, the VNS01 employs Visual Odometry (VO) and onboard sensor fusion to maintain reliable dead-reckoning navigation. By continuously tracking visual features and aircraft motion, the system maintains accurate relative positioning even in areas where no prior references are available. Terrain Referenced Navigation (TRN) provides an additional source of absolute positioning by correlating onboard terrain measurements with Digital Elevation Models (DEMs). Together, these capabilities continuously generate position corrections, keeping inertial navigation drift bounded and supporting long-endurance operations in contested GNSS-denied environments.
Through this combination of Visual Odometry, Pattern Recognition, preloaded Satellite Map Matching and Terrain Referenced Navigation, the system enables precise position updates both in known and unknown flight areas. Corrections generated by these algorithms are fused within the navigation estimator, allowing the Flight Control System to maintain bounded and stable navigation performance during prolonged GNSS outages.
This innovative capability is likely to attract attention from manufacturers and end-users of NATO Category I and II UAS, small and medium‑sized UAS. The compact and lightweight device, offered as an optional peripheral to the main Flight Control System (FCS), facilitates the safe and efficient navigation of Uncrewed Aerial Vehicles (UAVs) in GNSS-denied environments.
Map matching at work:
