HIGH RESOLUTION ACTIVE SONAR WAVEFORMS AND PROCESSING

THIS PROJECT WILL DEVELOP AND TEST HIGH RESOLUTION ACTIVE SONAR WAVEFORMS. THE HIGH RESOLUTION IS ACHIEVED BY COHERENTLY FREQUENCY HOPPING ELEMENTAL PULSES. THE HOPPING PATTERNS, WHICH ARE FROM THE SET OF BEST POSSIBLE PATTERNS, ARE EASILY GENERATED. A PRACTICAL RECEIVER PROCESSOR IS PROPOSED WHICH ACCOMODATS DIFFERENTIAL DOPPLER WITH LITTLE DEGRADATION. IT ALSO PROVIDES VERY HIGH RESISTANCE TO CW AND PULSED INTERFERENCE, AND PERMITS COHERENT INTEGRATION OVER THE AVAILABLE COHERENCE TIME OF THE CHANNEL. THE PROPOSED WAVEFORMS ARE BELIEVED TO BE CONSIDERABLY MORE EFFECTIVE IN EXTRACTING TARGET INFORMATION THAN LOW TIMEBANDWIDTH WAVEFORMS. A COMPUTER SIMULATION OR THE WAVEFORMS, THE CHANNEL INCLUDING TARGET, AND THE RECEIVER PROCESSING WILL BE WRITTEN AND USED TO VERIFY THE PREDICTED PERFORMANCE.