Spread Spectrum Techniques for Sonar Ping Technology

Spread spectrum signals have been successfully employed for many years in communications systems to transmit digital information when there is a need to combat the detrimental effects arising from various types of interference. More recently they have also been effectively employed in Low Probability of Intercept (LPI) and Low Probability of Identification (LPID) radar systems to minimize the impact of jamming and provide a method of hiding a signal by transmitting at low power. A spread spectrum approach for active sonar systems which requires less peak power offers the potential for improved detection performance while reducing the power requirements and the impact on marine life. We are proposing an investigation of the application of spread spectrum methods to continuously transmitted spread spectrum acoustic signals that would potentially improve active sonar detection performance by improving time-bandwidth gains and hence improve received SNR. The spread spectrum methods to be examined in this proposal will leverage previous experience with continuous active sonar technologies and significantly enhance target detection, classification and tracking processes for multi-static active ASW applications.