Kalman filter

Real-Time Wave and Boat Motion Estimation with Kalman Filtering

A Kalman filter is a precise tool for a chaotic environment, and that is exactly what this work brings to marine navigation.

3 min readoceanography: things about the sea

Open-source hardware and software projects rarely get the credit they deserve for advancing ocean science. The recent work by developer bearthesailor on a Kalman filter for real-time wave and boat motion estimation is a case in point. Using an IMU on an atomS3R unit, the project estimates boat heave and wave direction, and it accomplishes this with an OU-driven Quaternion MEKF for marine inertial navigation. This is not a simulation or a theoretical paper; it is a working implementation on a real device, with code openly available on GitHub under the Bareboat Necessities project called 'ocean-imu'.

What makes this contribution significant is its accessibility. We often discuss large-scale ocean monitoring in terms of satellite constellations and deep-sea observatories, but the reality is that a vast amount of practical maritime data begins with small, distributed sensor systems. This project fits neatly alongside broader efforts to democratize ocean data, such as Ukraine Supports India’s Initiative for Black Sea Shipping Routes, where geopolitical decisions ripple down to the safety of individual voyages. Similarly, understanding wave dynamics at a local level is a form of climate intelligence that informs everything from route planning to coastal resilience. The Kalman filter here is a classic, validated tool, but applying it on low-cost hardware in real time is a meaningful step toward making ocean intelligence more granular and immediate.

Our take is that this is the kind of empirical, peer-review-adjacent work that the marine community should watch closely. The code is open, which means it can be tested, calibrated, and improved by other developers and researchers. That is how shared infrastructure grows. We would tell a curious reader that this is not a consumer app; it is a building block for something larger. For a sailor, it could mean better sea-state awareness. For a researcher, it offers a baseline for comparing IMU-based estimates against buoy data. For a developer, it is a reference implementation of a quaternion-based MEKF that avoids the black-box approach of many commercial systems. The practical takeaway, and one worth quoting: "A low-cost IMU with an open-source Kalman filter can turn any small craft into a wave-state sensor."

The broader implication is that we are moving toward an integrated data ecosystem where longitudinal, real-time measurements from diverse platforms feed into climate indicators and ocean models. This project is a small but precise piece of that puzzle. What we will be watching is whether this codebase gains traction, whether it is adopted beyond the original author's vessel, and whether the wave-direction estimates hold up under varied sea states. In a field where Exploring Plankton Science: Accessible Research for Curious Ocean Observers shows how low-cost tools empower citizen science, and Extreme Thermophile Amoeba Expands Limits of Complex Life's Heat Tolerance reminds us of the extremes life and systems can endure, this project stands out for its practical utility. The open question is not whether the filter works, but who will pick it up and push it further.

From oceanography: things about the sea

I’ve designed and implemented a Kalman filter for boat movement in ocean waves using IMU. I thought it might be of interest to someone here.

Implementation on a real device uses atomS3R unit.

Read the original at oceanography: things about the sea