Interferometry in inertial navigation refers to the use of wave interference principles (typically light or radio waves) to measure precise motion, orientation, and distance. It is commonly applied in high-precision gyroscopes, such as Fiber Optic Gyroscopes (FOG) and Ring Laser Gyroscopes (RLG), which are essential for aerospace, defense, and submarine navigation.
How Interferometry Works in INS?
Wave Propagation – A light beam is split into two and sent in opposite directions within an optical fiber or ring laser cavity.
Sagnac Effect Detection – When the system rotates, the interference pattern of the recombined light changes, allowing precise angular velocity measurement.
Integration with INS – The measured rotation is used to calculate orientation and navigation data.
Applications of Interferometry in Inertial Navigation
✔ Fiber Optic Gyroscopes (FOG) – Uses optical fibers to measure rotation with high accuracy and no moving parts.
✔ Ring Laser Gyroscopes (RLG) – Employs laser interference in a closed cavity to achieve low-drift angular velocity measurement.
✔ Precision Navigation in GPS-Denied Environments – Used in submarines, spacecraft, and military systems where GNSS is unavailable.
Advantages of Interferometry-Based INS
✔ High Sensitivity & Accuracy – Measures extremely small rotational changes.
✔ No Moving Parts – Increases reliability and longevity compared to mechanical gyroscopes.
✔ Immune to Electromagnetic Interference (EMI) – Ideal for military and aerospace applications.
