Effects of Platform Motion on Microwave Radiometer Measurements

Offshore wind energy is a rapidly expanding sector and a key element of the transition toward sustainable energy systems. Accurate characterization of site conditions, such as wind speed, atmospheric stability, and metocean conditions, is essential for the planning, design, and operation of offshore wind farms.

While traditional meteorological masts can provide detailed measurements of these parameters, their installation and maintenance are costly. Consequently, floating lidar systems (FLS) have become the preferred alternative for offshore wind resource assessment, providing wind measurements together with selected meteorological and oceanographic parameters.

Mounting a microwave radiometer (MWR) on a floating platform would complement these measurements by providing continuous vertical profiles of temperature and humidity, enabling in-situ characterization of atmospheric stability. Atmospheric stability strongly influences boundary-layer structure, wind shear, and wake development and is therefore important for offshore wind resource assessment and modeling.

This study investigates the feasibility of such a concept by assessing the influence of platform motion on MWR measurements, which are used to derive stability parameter, such as the bulk Richardson number. Measurements from a motion-table-mounted, moving, uncompensated MWR are compared with those from a stationary system of the same type in an onshore experiment.

The results quantify the impact of platform motion on retrieved profiles and evaluate whether motion compensation is required for reliable deployment of MWR systems on floating platforms. The analysis includes controlled sinusoidal motion patterns (roll, pitch, and combined pitch \& roll) at three intensity levels, as well as realistic motion derived from floating platform measurements. The findings of this work contribute to the assessment of the feasibility of integrating MWR systems into floating platforms for offshore wind applications.