What is an Inertial Navigation System (INS) and how does it work?

An INS determines position, velocity, and attitude by measuring accelerations and rotation rates using inertial sensors (accelerometers and gyroscopes) and integrating them over time. Modern systems use ring laser gyros (RLG) or fiber optic gyros (FOG) instead of mechanical gyros. INS advantages: Completely self-contained (no external signals needed), Provides attitude reference, Not susceptible to jamming. Disadvantages: Errors accumulate over time (drift), Requires initialization (alignment), and More expensive than GPS. INS is typically combined with GPS in Inertial Reference Systems (IRS) for complementary benefits - INS provides short-term accuracy and attitude, GPS corrects long-term drift.