Passive Aero-Acoustic Sensor Self Interference Cancellation

The performance of aero-acoustic weapons systems mounted on army ground vehicle/weapon platforms is often seriously degraded by interference from engine noise, vibration and vehicle motion. The purpose of this project is to improve the performance of the acoustic sensors by cancelling or reducing the vehicle noise appearing in them, through the application of multi-channel noise cancellation. Others have previously tried to accomplish this by application of the classic Widrow algorithm for multichannel noise cancellation. The Principal Investigator of Signal Separation Technologies (SST) also has previously attempted to apply the classical algorithm, in his case to the elimination of tow cable strum induced vibration noise appearing in a Navy towed array sonar. Finding the classic algorithm to be theoretically and practically deficient for multichannel noise cancelling application, he augmented the algorithm to make it work correctly. This new method, termed the Signal-free Reference - Singular-value Decomposition (SFR-SVD method), was able to solve the sonar vibration noise cancelling problem. This method will be applied to the vehicle noise problem, and should yield similar benefits.