Algorithm Simulation And Dsp Realization Of Azimuth And Distance Estimation Of Underwater Target By Towed Line Array

Acoustic positioning system has wide application in the Ocean Scientific field. However, most existing systems have disadvantages of bulkiness, perplexing operation, limited position range or low precision, resulting in their incompetence of many application requirements. With the development of Acoustics and Signal Processing theory, it is possible for us to develop more advanced positioning systems. This article first reviews the principle and structure of three traditional kinds of acoustics position system, and analyses their performance in dividually. Some typical products are showed to illuminate the performance and the applieation. Based on acoustic positioning system, the signal processing software of the underwater acoustic measurement system is designed and realized in this dissertation. The system deals with the signal sent by cooperation sound source, the frequency, amplitude, delay, pulse width and other important parameters of the signal are estimated. The pulse of direct path is selected among detected pulses, and the time delay is used to real-time estimate the azimuth and distance of the goal.Azimuth and distance estimation of underwater target by towed line array is achieved on positioning for single underwater target using the technology of underwater acoustic positioning. The main work of this thesis is to realize the real time estimation of azimuth and distance of underwater target which satisfies the demand of testing of underwater acoustic, use of the existing digital signal processing platform. Content is divided into two parts: the study on the principle of algorithm and Matlab simulation; and the implementation of DSP program design.Time difference of arrival method used in this thesis is one of the most commonly used underwater acoustic passive localization algorithm, the algorithm according to the different arrival hydrophone array signal of the array relative delay time to estimate the target azimuth and distance parameter, the basic principle is to use time delay and hyperbolic intersection positioning. The signal detection and parameter estimation and positioning algorithm are all through simulation with MATLAB, and the signal processing application software using for measuring system are designed and debugged. The design and realization of every functional module about the software is discussed in the dissertation, the management and allocations of DSP resource and the communication between DSP and PC is also introduced. The results of simulation and laboratory debugging show that the algorithm is effective feasible.Digital signal processing platform uses two pieces of master-slave structure ADSP-TS101 as data processing center, uses one piece to complete A/D data acquisition and the preliminary processing of signal; another piece to complete underwater target signal detection and azimuth and distance calculation. Between two pieces of TS101 are connected by link port. Two DSP programs is accomplished by assembly language, in this hardware platform to implement data acquisition, signal real-time detection, azimuth and distance calculation function, through laboratory simulation, the program is running well, the treatment results is consistent with the theoretical analysis, the predefined requirements are fulfilled.