Stability increase of navigation systems based on the use of digital space shots of the territory as navigation fields and their comparison with digital images of the territory from drone camera in real time during its flight.  

One of the ways of increasing drone efficiency is to solve the task of their autonomous navigation during the flight in case of blocking the signal from the satellite navigation system. The advantage of autonomous passive navigation methods is the lack of any signals received by the drone, which makes impossible the action on it from outside and the lack of any signals from the drone. The solution of the autonomous navigation task can be implemented based on the use of digital maps of the territory as navigation fields. However, a number of difficulties can be faced due to the availability of suitable digital maps (scale, content, projection, parameters of land ellipsoid, coordinate system). One of the ways of overcoming these difficulties can be the use of space shots of the territory as navigation fields. In this case, the drone images are compared with the corresponding space images downloaded into the memory of the drone image analyzer, and the coordinates and parameters of the drone orientation relative to the indicated territory area can be the results of such comparison. The accessibility and quality of modern space images comparable with the quality of images from the drone camera allow quite operatively preparing the drone flight and controlling it in real time, adjusting the drone location based on the deviations from the planned flight route.
The research results allow creating quite new class of navigation devices and systems using it, and to qualitatively change the already available drones when equipping them with similar navigation systems. At present, there is no information about the industrial use of the systems of autonomous passive visual air navigation in any country of the world. However, based on the available publications such works are widely conducted.