US Patent 8742977 Wind turbine bird strike prevention system method and apparatus

A bistatic radar receiver is located on a wind turbine and surrounded by multiple bistatic transmitters to detect and precisely track the positions of nearby birds. Bird target reflections from multiple transmitters are received by the radar receiver and their position and track determined from the transmitter locations, receiver location, and measured transmitter-to-target-to-receiver ranges. Target position and altitude accuracy is similar to GPS. When birds are detected to be on a collision course with the wind turbine, a deterrent is activated to scare them away. Deterrents can be flashing strobe lights, intense sound, air cannon, or any other effective bird deterrent.