Design Of OBS Emplaced Short Baseline Positioning System

According to the location principle of intersection solution of short baseline TOA ranging,an underwater acoustic positioning system is designed to locate the location of OBS.The system has the characteristics of small size and low cost.The positioning system consists of two parts: beacon and array.The beacon is installed on the positioning target.The array takes the hull as the carrier and carries out synchronous positioning within 200 m.The positioning system combines with GPS system to convert the positioning coordinates into geodetic coordinate system.In this paper,the positioning model of the positioning system is analyzed.According to the design index,the positioning equations are optimized by a variety of positioning algorithms,and the positioning accuracy of each algorithm is simulated and analyzed by Monte Carlo method.By Geometric Dilution Of Precision,the influence of different formation on the positioning accuracy distribution is compared.The dual antenna differential GPS system is added to the array,and the relationship between the array coordinate system and the geodetic coordinate system is established by measuring the antenna vector.In TOA intersection calculation,the accuracy of time delay estimation is the main factor affecting the positioning accuracy.In this paper,Phat generalized cross-correlation method,which is easy to implement in engineering,is selected as the main time delay estimation algorithm of positioning system.In order to ensure the constant false alarm rate,constant false alarm detector is used to detect the correlation peak of time delay estimation.A vi-cfar detector with adjustable parameters is used.The detector determines the detection threshold by judging the noise background characteristics of the detection unit.The signal processing adopts the combination of envelope detection and generalized cross-correlation method to meet the requirements of calculation amount and accuracy.In this paper,the transmitter board and receiver board of the positioning system are designed.Finally,the received signal in the experimental pool is used to simulate the real signal,and the signal processing flow is improved by processing the experimental data.