Acoustic Security Detection System

Acoustic sensors can be a valuable aid to providing security surveillance of military bases, ships, and warehouses. To do so, the sensor system must be able to differentiate between "normal" sounds of nearby activity or the natural environment, and "security-breaching activity." SARA applies an inverse approach to this problem: An acoustic sensor that records and maps the features of every sound heard. After a period of adapting to a new environment, the system will report any new sound types heard. Therefore, any unusual sound triggers an alarm. This approach removes the need for tedious training of many samples of a large library of sounds, and allows the sensor to be deployed to entirely new environments or changing environments, without retraining or study of the acoustic environment. Sounds are characterized by signal features developed for voice recognition, music library searches, even from radar signature identification technology, to select a robust and unambiguous set of features. Operational factors, such as time-of-day and location of sound, are used to further evaluate the alarm condition. The proposed hardware for this sensor system takes advantage of sensor array processing techniques, and SARA's unique all-weather windscreen is used.