Scientists are just coming to appreciate the problems large fields of WTGs can cause for Air Traffic Control Radar and Weather Radar facilities.
Wind turbine generators (WTGs) are increasingly littering the landscape. However, their adverse impact on primary and secondary radar as well as Automatic Dependent Surveillance Broadcast (ADS-B) is just becoming appreciated. WTGs are known to produce false images (ghosts) on radar scopes that arise from a large group of WTGs (Wind Turbine Generator-Large Scale Deployment or WTG-LSD) producing reflective “hits” that the radar computer interprets as an aircraft “track.” Radar may follow this apparent aircraft “track” caused by random hits of the WTG-LSD blades on radar beams until the radar “hits” cease to line up or present themselves as an “aircraft track,” and the “ghost” disappears from the radar scope of the air traffic controller—only to re-emerge, again, if the blade reflections line up as an apparent aircraft “track” to the computer of the Air Traffic Control radar facility. Reflections from the blade tips of WTG-LSDs can “clutter” the air traffic controller’s radar scope with images of false returns the radar computer interprets as an “aircraft track.” Radar is designed to inhibit and not report stationary objects. However, the tips of the WTG blades may have a velocity of approximately 180 miles per hour reinforcing the computer’s belief it is actually “tracking” a moving aircraft as opposed to a blade tip attached to a stationary wind turbine generator.
While NEXT GEN (the Next Generation) of advanced aircraft tracking includes ADS-B, it is believed even this remarkable innovation in aircraft tracking is susceptible to WTG-LSD interference. ADS-B technology includes powerful multipath interference methods to prevent interference such as the reflective interference from an ADS-B signal striking a series of rotating blades in a WTG- LSD field. However, even this technology may be incapable of overcoming inter-symbol interference in ADS-B’s digital modulation, specifically multipath fast fading from an array of tightly-grouped radio-reflective surfaces (i.e., WTG-LSD fields).
Scientists are just coming to appreciate the problems large fields of WTGs can cause for Air Traffic Control Radar and Weather Radar facilities including NEXRAD Radar used by Air Traffic Control personnel and pilots for weather depiction and/or avoidance. These two videos, available on You Tube, demonstrate: (1) how a WTG hub can re-broadcast a digital television signal and (2) how a crane adjacent to a WTG can act as an antenna receiving electronic signals from a radio station.