| Target location technology has been widely used in military,aerospace and life.All countries in the world are studying the technology and equipment based on different positioning theory.In this paper,we discusses the TDOA passive positioning technique based on the range positioning project of The Institute of Acoustics of the Chinese Academy of Sciences.Considering the problems encountered in the actual project and the indexes in the experiment,we discusses and analyses from theoretical analysis to practical application in several aspects.The main contributions of this dissertation can be concluded as follows:1.In view of the low precision of time delay estimation caused by the differences between the hardware and the environment,a time delay calibration algorithm is proposed based on frequency-divided probability model(PFD-TDE).Based on the GCC algorithm,the received signal is segmented in the frequency domain,the frequency domain probability model of time delay estimation between each node and the reference node is established with a set of known training source data.Different measurement nodes have different probability model,which can calibrate the signal delay by the probability weighting of different frequency bands.2.This dissertation studies the single source TDOA location problem.After detailed analysis and comparison of the standard Chan algorithm and the improved Chan algorithm,we discuss two error correction algorithm based on the estimation errors of each stage in the two algorithms:Staged local correction and Global correction algorithm.Staged local correction algorithm correct the positioning error in each stage and assume the biased estimation of each stage is revised for the unbiased estimation after the correction.The global error correction algorithm analyze the relationship between the estimated values of each stage,and the error correction is performed at the final stage.Through simulation,we find the two kinds of error correction algorithms can effectively improve the location precision compared with the original algorithm,and the global error correction algorithm perform better than the local error correction algorithm.3.This dissertation studies the multi-source TDOA location problems.Aiming at different situations of multi-source,the 3 kinds of separation and localization algorithm is discussed.Firstly,according to the situation of multi-source with different features,we discuss a kind of separation and localization algorithm based on the similarity judgment.According to the situation of multi-source with similar features,we discuss the Search Matching algorithm and Multiple Baseline Joint Location algorithm.In order to achieve the separation of the multi-source,the Search Matching algorithm is cost of computational complexity.After the analysis of the received time sequence in the spatial distribution with multi-source on different position and firing interval,we discuss the Multiple Baseline Joint Location algorithm based on the hyperbolic characteristic of the received time sequence.The initial positioning result is obtained by the clustering result of the Chan algorithm with the short baseline array.The preliminary positioning results are fed back to the long baseline array,which can realize the accurate positioning of the binocular source.Simulation results show that all discussed algorithm can achieve the separation and localization of multi-source under a certain condition.4.At last,the dissertation discuss the positioning system of the range shell burst.We briefly introduce the composition of the positioning system,including the hardware part,the software part of the host computer and the TDOA positioning algorithm.The system focuses on the solution to ensure the synchronization of each node,by adding time scale signal and second pulse signal in hardware and then aligning the signal in algorithm,so as to improve the positioning accuracy of TDOA.By an experimental test on the shell burst point in 2016,we test the system. |
PDF Full Text Request