| This project consisted of a feasibility study to ascertain whether or not an inexpensive acoustic modem for an Autonomous Underwater Vehicle (AUV) could be developed using low cost commercially available products. Our AUV's at Florida Atlantic University currently use LonWorks for their internal control networks, so we have plenty of experience with their parts. The LonWorks Power Line Transceivers are capable of generating a signal that can be sent to a transducer for communication through the water. The PLT-30 Power Line Transceiver generates a direct sequence spread spectrum signal (DSSS) that offers many useful operating features; such as anti-jam, interference rejection and covert communications, low intercept probability, and most importantly, multipath protection. After numerous tests, however, the system was incapable of establishing reliable acoustic communications. We conclude that the PLT-30 Power Line Transceiver use as an underwater acoustic modem is not a viable approach. As an alternative method, communication through an electric current field was tested in a salt-water pool. The initial test produced a 100% success rate. |
