Drones navigate using a combination of sensors, GPS (Global Positioning System), and onboard processing. Here's how it works:

1. **GPS**: GPS receivers on the drone receive signals from satellites orbiting the Earth, allowing the drone to determine its precise location in three-dimensional space. GPS provides essential navigation data, including latitude, longitude, altitude, and velocity.

2. **Inertial Measurement Unit (IMU)**: IMU sensors, such as accelerometers and gyroscopes, measure the drone's acceleration and rotation rates in all three axes. This data helps the drone determine its orientation and maintain stability during flight.

3. **Barometer and Altitude Sensors**: Barometers and altitude sensors measure air pressure or altitude above sea level, allowing the drone to maintain a stable altitude and adjust its flight path as needed.

4. **Compass**: Compass sensors provide the drone with directional information, helping it maintain a consistent heading and navigate along predetermined flight paths.

5. **Vision Sensors**: Vision sensors, such as cameras or depth cameras, capture images or depth information of the drone's surroundings. Computer vision algorithms analyze this data to detect and avoid obstacles, identify landmarks, and navigate in complex environments.

6. **Radio Control Signals**: In manual mode, the drone can be controlled directly by a pilot using a remote controller or transmitter. Radio control signals sent by the pilot adjust the drone's throttle, pitch, roll, and yaw to control its movement.

7. **Flight Controller**: The flight controller is the brain of the drone, responsible for processing sensor data, executing control algorithms, and generating commands to adjust the drone's flight dynamics. The flight controller continuously evaluates navigation inputs and adjusts the drone's orientation, speed, and trajectory to navigate toward the desired destination.

By integrating these navigation systems and sensors, drones can autonomously navigate through various environments, follow predefined flight paths, and execute complex maneuvers with precision and reliability.