LainePoiss—a lightweight and ice-resistant wave buoy

Abstract

Wave buoys are a popular choice for measuring sea surface waves, and there is also an increasing interest for wave information from ice-covered water bodies. Such measurements require cost-effective, easily deployable, and robust devices. We have developed LainePoiss (LP)---an ice-resistant and lightweight wave buoy. It calculates the surface elevation by double integrating the data from the inertial sensors of the micro-electromechanical system (MEMS), and transmits wave parameters and spectra in real-time over cellular or satellite networks. LP was validated through: 1) sensor tests, 2) wave tank experiments, 3) a field validation against a Directional Waverider, 4) an inter-comparison of several buoys in the field, and 5) field measurements in the Baltic Sea marginal ice zone. These extensive field and laboratory tests confirmed that LP performed well (e.g., the bias of significant wave height in the field was 0.01 m, correlation 0.99 and scatter index of 8 %). LP was also deployed with an Unmanned Aerial Vehicle and we present our experience of such operations. One issue that requires further development is the presence of low-frequency artefacts caused by the dynamic noise of the gyroscope. For now, a correction method is presented to deal with the noise.