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GuideNav, a developer of inertial sensing and navigation solutions, explains the practical differences between Fiber Optic Gyroscopes (FOG) and MEMS-based Inertial Measurement Units (IMUs) for subsea navigation in GPS-denied environments. Read more >>
Subsea navigation depends entirely on inertial sensors, as GPS signals do not penetrate underwater and even small drift rates can grow into major positional errors over long missions. Selecting the right inertial technology is therefore critical to mission success.
Fiber Optic Gyroscopes (FOG) provide ultra-low drift, long-term stability, and consistent performance in harsh, GNSS-denied subsea environments. Although they involve higher upfront cost, their long service life and minimal recalibration requirements often deliver lower lifecycle cost for operators conducting repeated long-duration or high-precision missions.
FOG-based systems support survey-grade mapping, accurate georeferencing, and stable navigation for defense-grade Autonomous Underwater Vehicles (AUVs), deep-sea research vehicles, and offshore oil and gas survey platforms.
MEMS-based IMUs offer a compact, low-power, and cost-effective alternative for platforms with less demanding accuracy requirements.
While MEMS sensors exhibit higher noise and drift and typically require more frequent recalibration or algorithmic compensation, they provide sufficient performance for short-duration and cost-sensitive tasks such as hull inspection, harbor surveillance, shallow-water operations, and lightweight Remotely Operated Vehicle (ROV) deployments. Their small size and affordability enable flexible system design, redundancy, and use on disposable platforms.
Across cost, maintenance, data quality, and proven applications, FOG remains the preferred choice for long-range, mission-critical subsea navigation, while MEMS is well suited to smaller platforms and short-term missions. The appropriate sensor technology ultimately depends on the platform’s mission profile and the balance between precision, endurance, size, power, and budget.
To find out more information, read ‘FOG vs MEMS in Subsea Navigation: Which One Holds Better? (Part II)’ here >>
