Audio Telescope May Avert Bird-Plane Collisions
A public-private team of researchers has developed an “audio telescope” that could help airports avoid costly and hazardous bird-aircraft collisions by locating and identifying birds by their calls.
The concentric array of 192 microphones, measuring 39 ins. in diameter, would be mounted parallel to the ground to listen to the skies.
Researchers at the National Institute of Standards and Technology (NIST), Intelligent Automation, Inc., and the University of Missouri-Columbia have modified an NIST-designed microphone array to make the audio telescope.
Collisions with birds in flight, called “bird strikes,” have caused over $2 billion of damage to aircraft in the United States or U.S. aircraft abroad since 1990, according to statistics from the Federal Aviation Administration (FAA).
Wildlife strikes, mostly birds, have destroyed more than 163 aircraft and killed more than 194 people worldwide since 1988.
Airports use X-band radar and infrared cameras to monitor birds, but neither technology can distinguish between different kinds of birds, particularly in bad weather. Not all birds are equally hazardous to aircraft, and closing runways because of the proximity of unknown birds imposes costs in delays and increased aircraft congestion.
By comparing the arrival time of sounds at different microphones, the array can determine the direction from which the sounds came, even distinguishing simultaneous sounds coming from different directions.
The researchers adapted mathematical algorithms designed to allow speech recognition systems to identify different speakers in order to distinguish different species by their calls. The system can tell a Canada goose from a gull or a hawk within a few seconds.
The U.S. Air Force Office of Scientific Research funded development of the prototype.