The safe operation of Unmanned Aerial Systems (UAS) depends in most cases strongly on the availability of a GNSS (Global Navigation Satellite System) positioning solution to ensure navigation capabilities. This is essential for beyond visual line of sight (BVLOS) missions, since manual control through the visual line of sight of the pilot is not possible. Additionally, GNSS signals are vulnerable through accidental or deliberate interference. This paper proposes the use ofTime-of-Flight (ToF) measurements provided by a data link as an additional, independent and operator autonomous positioning system. The characteristic low update rate (ca. 1 Hz) and low precision (ca. 30 m) of the ToF measurements are analyzed with respect to their suitability for incorporation into a sensor fusion algorithm utilizing an error-state Kalman filter. For 2-dimensional multilateration, a set of two ground based data link segments and one platform fixed data link segment are used. As a data link solution, the Silvus StreamCaster 4200 Enhanced Pluso̧pyright is chosen. The ToF measurements between each of the link segments are here readily available. The influence on the position solution by the coarse ToF measurement, as well as the relative position between the ground stations and the platform is analyzed. In combination with a Pixhawk 6x\p̧yright, two ToF measurements were integrated and tested in the field. The drift of the strapdown navigation could be compensated and a stable navigation solution that is sufficient for emergency situations, such as enabling the UAV to return to VLOS, can be achieved.     «

The safe operation of Unmanned Aerial Systems (UAS) depends in most cases strongly on the availability of a GNSS (Global Navigation Satellite System) positioning solution to ensure navigation capabilities. This is essential for beyond visual line of sight (BVLOS) missions, since manual control through the visual line of sight of the pilot is not possible. Additionally, GNSS signals are vulnerable through accidental or deliberate interference. This paper proposes the use ofTime-of-Flight (ToF) me...     »