Research On Passive Ranging Technology Of Underwater Acoustic Pulse Signal

The passive ranging problem of underwater acoustic pulse signal has always been a difficult point in the field of underwater acoustic signal processing.Based on the basic theory and models of passive ranging,combined with the characteristics of non-cooperative pulse signals,the methods of target motion analysis(TMA)and direct positioning determination(DPD)methods are studied in this dissertation.The specific work is as follows:By modeling the performance of the TMA ranging model based on pulse parameter estimation,the impact of estimation accuracy of pulse parameters on the system’s ranging performance is analyzed in this dissertation.The parameters include direction of arrival(DOA),frequency of arrival(FOA)and time of arrival(TOA).Aiming at the passive ranging problem of TMA,the ranging performance of the TMA model based on either DOA-FOA or DOA-TOA is analyzed in detail.An improved Unscented Kalman Filter(UKF)positioning method based on DOA-TOA is proposed in this dissertation.Firstly,the moving average filter(MAF)method is used to smooth the observation parameters.Then the pseudo-linear estimation(PLE)method is used to calculate the initial value of the target state quantity.Finally,UKF method is used to track the target trajectory.The results of simulation analysis and sea trials show that the improved UKF method can effectively improve the ranging accuracy of the TMA method.Aiming at the problem of passive ranging problem of DPD,the ranging performance of the DPD model based on single-array using Doppler is studied.In view of the known and unknown frequency,a DPD ranging algorithm based on multi-element array is proposed under the condition of unknown frequency.The characteristics of the array makes the system’s ranging performance significantly improved.When the frequency is unknown,the distance measurement is realized by pre-estimating the signal frequency and expanding the search dimension.The results of simulation analysis and sea trials show that the DPD ranging algorithm based on multi-element array can effectively improve the ranging performance of the system.