Inertial Navigation Systems are electronic systems that monitor the location, velocity, and acceleration of a vehicle, often a submarine, missile, or airplane. This enables sharing of navigational data or control without requiring communication with a base station.

At least three gyros and three accelerometers are used in an INS system to obtain a navigation solution. At the very least, this navigation solution comprises the position (normally latitude, longitude). Today, the majority of Inertial Navigation Systems output heading, pitch, and roll. Additionally, some systems incorporate heave, sway, and surge.

Benefits and Drawbacks to INS systems are operated automatically and do not require external assistance or visibility conditions to function. This enables them to function in tunnels and beneath the sea, as well as in stealth applications, as there is no external antenna that may be detected by radar. They are well-suited for integrated vehicle navigation, guiding, and control. The IMU of a system collects data on factors such as location, velocity, and altitude.

One downside of Inertial Navigation Systems is the high cost associated with the purchase, operation, and maintenance of the systems. Additionally, navigation mistakes and heat dissipation are negatives. Although the size, weight, and power requirements are still greater than those for GPS receivers, they are decreasing in size and power consumption with time and technical advancement.