HF Radar Wind Turbine Interference Mitigation

Presentation Description: Coastal oceanographic high-frequency surface wave radars (HFR), whose signals follow the curvature of the ocean surface beyond the horizon, measure the surface currents and waves of the coastal ocean over tens of thousands of square kilometers with high spatial and temporal resolution. The most common coastal HFR is the SeaSonde® compact cross loop system produced by CODAR Ocean Sensors Ltd. The 2-D surface currents from the U.S. national HFR network funded by NOAA IOOS are vital to the U.S. Coast Guard for search and rescue and oil spill response. HFR current data is integrated into large-scale operational forecasting models such as NOAA’s West Coast Operational Forecast System, a valuable tool for coastal industries and communities. Additional HFR data products such as wave, vessel and tsunami detection are now being adopted as part of operational coastal ocean observation networks. The next decade will see an increase in the number of offshore wind turbines, which, in the observation area of an HFR, act as reflectors that modulate the transmission and cause an interference signal that mixes with the sea echo causing errors in the data products. Existing mitigation techniques are designed to detect and remove oceanographic data impacted by WTI causing data loss. This work shows that the impact of removing data from HFR due to WTI is reduced by increasing radar redundancy using increased numbers of radars or operating radars in multi-static mode.