Acoustic tracking of small aircraft within an airport

Alexander Sedunov; Alexander Sutin; Nikolay Sedunov; Hady Salloum; Alexander Yakubovskiy; David Masters ASA meeting 2015 Jacksonville, FL 2015.11.02

Runway Safety at Airports

• Preventing runway incursions by unauthorized aircraft is a major component of airport safety

• Typical radar based ground monitoring equipment is too expensive to install in smaller airports

• Presenting experiment in repurposing a passive acoustic technology for Low-Flying Aircraft detection * for tracking of aircraft in airport

Image FAA Pilot’s Guide to Runway Safety http://www.faa.gov/runwaysafety

*Salloum, H.; Sedunov, A.; Sedunov, N.; Sutin, A.; Masters, D., "Acoustic system for Low Flying Aircraft detection," in Technologies for Homeland Security (HST), 2015 IEEE International Symposium on , vol., no., pp.1-6, 14-16 April 2015

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Acoustic Nodes

Microphones

Recorder

Acoustic node + 3-microhone array

900MHz Comms

Acoustic node + 5 microphone volumetric array

Electronics

Microphones

Node with plane array (lower resolution)

Full node with volumetric array of microphones

Cross-correlation TDOA finding

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Theoretical Performance of Pair-Wise Direction Finding (Average SNR)

Sensor geometry and possible cross-correlation pairs

Azimuth accuracy for target at 0 elevation

3-sensor node

5-sensor node (10 cross-correlation pairs)

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Map of Deployment for the Experiment

Acoustic nodes with volumetric array

Processing and display

Acoustic node with plane array

900MHz link

900MHz link

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Variation of Received Signal Spectra

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Comparison of Received Spectra between types of Aircraft

Bell 206B helicopter landing (passing) at 200m

C172S taking off at 200m

C172S taxi at 200m

Background noise

Fixed wing aircraft have significant variation depending on activity.

Tracking of Target and Geometric Factors.

Track established inside geometry

Artifact due to geometric factors

Track maintained using Kalman filter

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Tracking method explained in more detail in prior publication: Passive acoustic localization of small aircraft. Sedunov, Alexander and Sutin, Alexander and Salloum, Hady and Sedunov, Nikolay and Masters, David, Proceedings of Meetings on Acoustics, 20, 055005 (2015).

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Cooperation of Heterogeneous Nodes (Using the Third Node)

Full node with volumetric array of microphones

Fused position estimate 8 degree azimuth

error variance

4 degree azimuth error variance

Node with plane array (no elevation, lower resolution)

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Cessna Plane (C172/G) Taking Off

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Tracked aircraft

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Aircraft seen gaining altitude

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Cessna Plane on the Ground

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Tracked aircraft

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Track of a Helicopter During Landing

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Tracked aircraft

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Elevation

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Acknowledgement The Acoustic Aircraft Detection system development was funded by the U.S. Department of Homeland Security’s Science and Technology Directorate. The views and conclusions contained in this paper are those of the authors and should not necessarily be interpreted as representing the official policies, either expressed or implied of the U.S. Department of Homeland Security.

Visualization Software was Provided by BridgeNet.

Support for this experiment was provides by Essex County Airport (Fairfield, NJ) administration.

Conclusion We presented results of application of passive acoustics with sparse volumetric and plane arrays for tracking aircraft in three dimensions in the -course of daily airport activity. We were successful in tracking the targets and the altitude estimate has been shown usable for detecting whether aircraft is taking off or landing. Different small aircraft were recorded during several distinct activities (that are part of everyday airport traffic) while within the airport and variation of the level and spectral content of emitted noise.

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Example Plan for Complete Coverage

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10-14 stations recommended (not all nodes have to be full nodes)