Design On Acoustic Signal Simulator Of Active And Passive Acoustic Positioning System

Active/Passive underwater acoustic positioning system is a kind of acoustic measuring equipment for locating underwater targets in either active or passive operating mode. A passive positioning system relies on the radiated noise from target to locate without cooperation acoustic beacons, and an active positioning system does need to utilize the cooperation signal transmitted by the underwater moving targets to locate. The main contents of this dissertation are the design of acoustic signal simulator electronic platform for active / passive underwater acoustic positioning system.Underwater Acoustic transmitters play a decisive roll in the underwater systems, such as underwater acoustic positioning, navigation, or detection systems, the performance of the transmitters directly affect the whole system in important indexes such as positioning accuracy, operating range. This dissertation generally discussed the acoustic signal simulator such as design requirements, external interface, and then discussed the design of the system in detail, introduced every module such as driving signal generator, power amplifier, transducer matching respectively, especially focused on the driving signal generator whose core processor is the large-scale field programmable gate array(FPGA) EP1C6Q240C8 from the ALTERA company. Besides, this dissertation discussed the efficiency of various forms of power amplification principally, and presented the design principle based on class D power amplifier, designed an impedance matching network whose cores are transformer and series/parallel resonant circuit. Finally, an approximate lookup table algorithm based on Quasi-physical Algorithm used by the FPGA to generate the active / passive signals is proposed, and the simulation result are shown in the thesis.In the Songhua Lake, the active/ passive acoustic positioning system trial is completed with the acoustic Signal simulator. By comparing with the original signal received by the buoy array, the results show that acoustic signal simulator can simulate underwater moving acoustic source in either active or passive working modes.