A proliferation of large wind farms in recent years has posed a new challenge to both air traffic control and the renewable energy industry. The rotating blades of wind turbines can appear as false aircraft returns on air traffic and other radars. This clutter can lead to radars becoming de-sensitized in the area of the wind farms, resulting in genuine aircraft tracks being all too easily lost. This phenomenon has already prevented or delayed the establishment of new wind farms due to objections from aviation authorities.

Danish company Terma (Hall 2 Stand C26) has developed a solution in the form of the Scanter 4002 radar, which mitigates against the unwanted clutter from wind turbines. With an instrumented range of up to 40 nautical miles and capable of tracking aircraft at up to 40,000-feet altitude, the Scanter 4002 is a 360-degree, two-dimensional X-band radar that can be integrated alongside existing air traffic radars. It can cover areas with multiple wind farms, and can even track aircraft between individual turbines.

Terma has demonstrated the capability of Scanter 4002 as part of the U.S. government’s inter-agency field test and evaluation (IFT&E) effort. Joining this program in October 2012, Terma used a Scanter 4002 to scan an area near Abilene, Texas, that had more than 500 wind turbines within line-of-sight. Comparison of data from the radar with GPS data from target aircraft showed that an unprecedented 98 percent were accurately tracked over the wind farm. Tracking data was well within the specifications required by air traffic control radars, while false alarm rates remained very low.