What is inertial navigation?

Inertial navigation is a method that relies on measuring velocity and acceleration to calculate the position of an object over time. This system uses inertial sensors such as accelerometers and gyroscopes to continuously measure changes in the object's motion. By integrating these measurements over time, the system can determine the object's current position, velocity, and orientation relative to its initial starting point. This technique is particularly valuable in aviation and aerospace applications, where GPS signals may be unavailable or unreliable, as it allows for autonomous navigation without the need for external references.

The other options describe different navigation methods. Celestial navigation is based on the positions of celestial bodies rather than inertial measurements. Ground-based markers are used in methods like triangulation or visual navigation but do not fit the definition of inertial navigation, which does not rely on external physical references. Lastly, radio signal navigation typically involves systems like GPS, where external signals provide location data, which contrasts with the self-contained nature of inertial navigation.