Submarine Detection by Acoustic Retina Network

Detecting submarines is inherently difficult, and particularly so in littoral areas. A detection system is needed that would consist of thousands of inexpensive sensors to detect a nearby submarine. In response to this need, Physical Optics Corporationproposes to develop the new STARFISH system. The central element of the system is an inexpensive sensor node combining a Kynar film acoustic transducer, thin film battery, MEMS pressure or magnetorestrictive sensor, and microprocessor mounted on a stripof biodegradable plastic. The combined sensor is designed for high volume web production at low cost. The strips are scattered by air or sea, and then establish a network by sending simple acoustic chirps to designated concentration sensors, whichconcentrate and preprocess the information in the fashion of a neural net. When a detector senses a contact or notices an occlusion of the chirps from its neighbors it generates a detection chirp, which is processed by the concentration nodes. When apattern of detections is recognized, the secondary nodes generate distinctive chirps that are detected and located by a small array of sonobuoys. STARFISH systems will be the underwater equivalent of radio frequency identification (RFID) tags forinventorying and tracking submerged objects for oil and gas exploration and extraction and other industries. Equipped with chemical sensors, a STARFISH system could cost-effectively detect and track coastal pollution over broad areas.