In modern warfare, the navigation of drones has become one of the key technological tasks. Most drones use satellite navigation systems, but in combat conditions the GNSS signal can be suppressed or distorted by electronic warfare assets. In such situations, a drone can lose its precise coordinates and flight stability.
To maintain controllability and the ability to carry out tasks, modern drones use alternative navigation methods. These include inertial navigation systems, computer vision technologies, and SLAM algorithms, which make it possible to determine the position of a drone without the direct use of satellite signals.
Why Drones Lose the GNSS Signal in Combat Conditions
GNSS is the general name for satellite navigation systems, which include GPS, Galileo, BeiDou, and GLONASS. Most civilian and military drones use such systems to determine coordinates, speed, and flight altitude.
In combat conditions, the GNSS signal can be lost due to the active operation of electronic warfare assets. Such systems can create radio interference or transmit false signals, which lead to the disorientation of navigation modules.
In addition to active interference, the stability of the signal can be affected by natural factors: the terrain, dense development, or weather conditions. As a result, a drone can lose navigation accuracy or switch to emergency control mode. More about the impact of such factors can be read in the article: «The impact of EW assets on GPS», which examines how electronic warfare affects the operation of satellite systems.
Inertial Navigation Systems in Drones
Inertial navigation systems make it possible to determine the position of a drone without using satellite signals. They work on the basis of acceleration sensors and gyroscopes, which measure the movement of the craft in space.
Such systems are part of most modern flight controllers. During flight, inertial sensors constantly record the change in the position of the drone and transmit this data to the control system.
The main advantage of inertial navigation is its autonomy. It does not depend on external signals and can work even in an environment of active radio interference. However, over time an error accumulates in such systems, so inertial navigation is usually used in combination with other technologies.
SLAM Technology in Drone Navigation Without GPS
SLAM (Simultaneous Localization and Mapping) is a technology that allows a drone to simultaneously build a map of the surrounding environment and determine its own position in space.
For this, cameras, lidar, or other sensors are used, which analyze surrounding objects. Computer vision algorithms identify characteristic points in the environment and track their change during movement.
Thanks to this, a drone can determine its position even without a satellite signal. Such technologies are actively used in robotics, autonomous transport, and modern unmanned systems.
Visual Navigation of Drones Using Cameras
Visual navigation is one of the areas of development of autonomous unmanned systems. In this case, the drone uses cameras to analyze the surrounding environment and determine its position relative to objects.
The algorithms analyze surface textures, the contours of buildings, or natural landmarks. By comparing successive images, the system can determine the direction of movement and the speed of displacement.
Such systems are especially effective in an environment where visual context is available: in urban conditions, among buildings, or natural objects. However, in open spaces with a small number of landmarks, the effectiveness of such methods can decrease.
Combining GNSS, SLAM, and Inertial Navigation
In modern drones, navigation systems usually work in a combined mode. Data from GNSS, inertial sensors, and SLAM algorithms is combined into a single flight control system.
Such an approach makes it possible to increase the stability of navigation. If the GNSS signal temporarily disappears, the inertial system can maintain flight stability, and computer vision algorithms help refine the position of the craft.
Similar principles are applied in modern unmanned platforms, in particular in FPV drones. For example, the «Zhakh 13” FPV Drone from BlueBird Tech is created to carry out tactical tasks in a difficult environment, where it is important to ensure the stability of flight and signal transmission. Such platforms can be used as standalone unmanned systems or work as part of more complex tactical complexes.
Limitations of Navigation Without GPS in Combat Conditions
Despite the development of autonomous systems, navigation without GPS has certain limitations. Inertial systems accumulate errors over time, which can lead to a gradual decrease in positioning accuracy.
SLAM and visual navigation technologies depend on the presence of objects in the environment. In areas with uniform terrain or in difficult weather conditions, the effectiveness of such algorithms can decrease.
It is also important to take into account computational resources. Complex navigation algorithms require powerful processors and energy consumption, which can affect the flight time of a drone.
Conclusions
Navigation without GPS has become an important area of development of modern unmanned systems. In combat conditions, the GNSS signal can be lost due to the operation of electronic warfare assets or other factors, so alternative technologies acquire special importance.
Inertial navigation systems, SLAM algorithms, and visual methods allow drones to maintain flight stability even in a difficult electromagnetic environment. The most effective approach is the combination of several technologies in a single navigation system.