This course covers Inertial Navigation Systems (INS) and Inertial Reference Systems (IRS). INS, which can be stand-alone systems, have historically been referred to as 'self-contained navigation systems' using gyro-stabilised platforms for dead reckoning. IRS, on the other hand, are typically integrated into a flight management system (FMS) and provide inertial data to other aircraft systems. Modern INSs often describe inertial platforms, IRSs and Inertial Reference Units (IRUs), typically installed on an aircraft. The course discusses the basic principles of inertial navigation, including double integration of measured accelerations in all three directions, initial position determination, and required corrections such as transport precession, Earth rate precession, Coriolis effects, and gravity.