Background: Flight vehicle in-situ aeroacoustic noise measurements are primarily obtained by flying an aircraft above ground based microphone arrays, or, by using pole-mounted linear arrays. This classic approach limits the altitude and variety of maneuvers for which these measurements can be obtained as well as contaminates the data with unwanted ground reflections. A novel approach is needed to acquire this and other flight and ground based vehicle acoustic signatures.
Technology:David Alvord and Alessio Medda from GTRI at Georgia Tech have developed an airborne acoustic testbed that consists of a self-contained acoustic sensing payload installed on an Unmanned Air Vehicle (UAV). The acoustic payload can be integrated with any type of UAV and used with additional data streams such as EO/IR or telemetry data. Using the developed signal processing suite, noise sources including self-generated UAV noise, wind, or environmental noise can be removed from the acquired acoustic signal of interest. Future capabilities of the AATB will include live voice acquisition, source localization, or acoustic fingerprinting.
The algorithm suite includes digital signal processing algorithms and post-processing functionality to filter the signal, account for flight operations, and process data from distributed microphones (both onboard as an acoustic phased array or across multiple UAVs). Future capabilities that can be developed using distributed acoustic phased arrays across multiple UAVs include speech detection, phased-array beamforming for complex ground source localization, synthetic apertures for infrasonic measurements, and aerial arrays for 3D acoustic environmental source characterization.
Applications: This invention creates an “ear-in-the-sky” capability,
being able to fly an UAV to a designated position and listen. Further possible applications include
acquiring acoustic characterization data for a specified vehicle from in
flight, acquiring ground based speech, Intel/Surveillance/Recon (ISR)
capabilities, detecting and localizing where a sound source of interest is
located, detecting search and rescue targets, and increasing situational
awareness and information.
Benefits / Advantages:
Overcomes limitations of
ground-based acoustic signal acquisition of flight vehicles by minimizing the
effect of ground reflections
Can be deployed on an
UAV swarm to acquire data simultaneously from multiple aircraft to map an
acoustic environment of interest
Can use acoustic beamforming
for ground target identification and localization
Capable of acquiring
acoustic signature data for a wider range of flight/ground vehicle maneuvers
Can be used for adaptive
autonomous flight control based on localizing a signal of interest