Research On Key Techniques Of Underwater Positioning For High Speed Cooperation Target

Recently,along with various countries attaching great importance to the rights of ocean and the construction of the coast defenses,acoustics technology becomes one of the most effective methods in underwater acoustic positioning and important part of oceanic technology.The combination of long baseline acoustic positioning technology was operated by synchronous acoustic beacons on Underwater positioning system of high speed cooperation target.High-precision positioning tragedy was used to locate of high speed cooperation target and trajectory of target was displayed on computer timely.We presents these parts of the Underwater positioning system: signal processing,detection and parameter estimation approaches.Firstly,we presented the signal pre-processing approaches in Underwater positioning system of high speed cooperation target,derived the adaptive Notch filter and demonstrated its performance using different parameters by simulation analysis.Since the multi-channel of the system,we contrasted the performance of multi-channel adaptive Notch filter with the single-channel ones.Results shows that multi-channel parallel adaptive Notch filter performs better in multi frequency signal.In second part,we proposed two strategies of signal detection based on restraining signal leakage among different channel and anti-multi-path.Firstly,Variance-of-InstantaneousFrequency Detector(VIFD)include envelope detection,width discriminator and VIFD detector was used to restrain signal leakage among different channel.The performance analysis of VIFD was carried out by simulation.Secondly,we presented the strategy include double width judgment and time interval judgment to overcome multi-path effect,the effects were verified by simulation.As for the parameter estimation,we researched on time-delay estimation approach using phase compensation and adaptive frequency estimation approach using frequency automatically tracking.Corresponding approaches were simulated in different SNR situations.Finally,the capability of these approaches was verified by electricity simulator in laboratory and trials in lake,which is robust and effective in operation.