Inertial navigation system (INS): Inertial navigation system calculates the position, orientation and velocity of aircraft by using motion sensors that is
accelerometers and rotation sensors that is gyroscopes and computer. Inertial sensors are also supplemented with barometric altimeter and magnetometers. It also uses global navigation satellite system (GNSS) receiver. INS receives information from motion sensors and rotation sensors and data from global navigation satellite system (GNSS) receiver and provide information about absolute position in latitude, longitude and altitude and absolute attitude in terms of roll, pitch and heading to the host computer.

The data received from global navigation satellite system improves accuracy of INS by compensating drift which occurs from small errors in data given by motion sensors and rotation sensors.

INS does not use any external references to find object’s position and orientation.

INS is used in aerospace applications, autonomous vehicles, robotics, industrial machinery mobile mapping etc.

Inertial reference system: Inertial reference system consists of gyroscopes, accelerometers, electronics system to calculate precise velocity, attitude and navigation information about an aircraft. Inertial reference system gives information about attitude, roll and pitch attitude, position, linear and angular velocity, linear and and angular acceleration, magnetic heading and true heading, azimuth tec.

Inertial reference system is the main component of the inertial navigation system and shows pilot the location of aircraft even when GPS signals are not received.