Aerospace Instrument-Making Annotation << Back REDUCING THE TRAJECTORY OF AN UNMANNED LOW-FLYING VEHICLE WITHOUT USING A PRIORI INFORMATION ABOUT THE PHYSICAL FIELDS OF THE EARTH A.Yu. Knyazhsky, A.V. Nebylov The article proposes a method for forming a low-altitude trajectory of an unmanned low-flying vehicle, laid mainly over lower terrain, based on data on point slant ranges, current own motion parameters and a given end point of the route. The effectiveness of the proposed method was evaluated by computer simulation of UAV movement in mountainous areas. The simulation results showed that, depending on the location of the start and end points of the trajectory, the terrain, the size of the sector of permitted movement and the characteristics of the UAV, the average height of the trajectory decreases by approximately 200–600 m, which allows moving signifi cantly below the tops of the terrain. Keywords: UAVs, unmanned aerial vehicles, height minimization, trajectory optimization, motion control. DOI: 10.25791/aviakosmos.5.2022.1278 Pp. 14-22.