The Research And Application About Generalized Correlation In Passive TDOA Location

Passive TDOA location is a technology designed to determine the target location. When the target radiates electromagnetic or acoustic signals, receivers located at different positions will get the signals in the respective time, from these signals to calculate the time difference. Then we can locate the target through a certain location algorithm. In practice, the choice of a wide dynamic fast response receiver station is necessary, combined with high-precision satellite synchronous time system to get accurate time delay information. Then through the effective location algorithm, a large number of real-time data for effective process, fast response, eliminate blur point, which can accurately indicate the actual location of the target source. In this process, it requires a combination of geographic information system(GIS) technologies to achieve a good user interface to meet customer’s intuitive and clear demand. According to different characteristics of target, such as position, velocity, radiation intensity, frequency, status or environmental characteristics, it requires different delay estimation algorithms and located algorithms to deal with.The paper focuses on the simulation and application of GCC algorithms in TDOA positioning system. By building a station platform based on SDR technology, consist of a basic three-station positioning network. On this basis, we acquire signal data under various conditions. Then the position of the target can be estimated by measuring real-world signal parameters. The practical application have a certain requirements for positioning accuracy, but the estimation accuracy is associated with many factors, there is some interference caused by different external environment, some other exist in system itself. These factors include receiver frequency offset, the types of the received signals, the sampling rates, channel types, the weighting factors and time synchronization system. The frequency offset of receiver is mainly due to receiver frequency error and Doppler shift which makes monitoring signal case a slow frequency drift phenomena, which has a greater impact on the performance of the receiver, TDE accuracy is also a factor needed to be corrected. Correspondingly different types of signals require different modes of filtering and demodulation modes to process. In actual environment, interference is not the same usually, at the receiving part, different approaches need to be analyzed to adaptively receive and demodulate. Sample rates and signal types are related with systems of their own hardware-related conditions, which can be obtained by empirical test data analysis. Channel types and weighting factors are two interrelated factors, also need to be considered in simultaneous analysis of real data. Time synchronization system has important implications in the TDE, the existing some products of domestic manufacturers have some problems on stable accuracy. In the practical application it is necessary to execute constantly test, analysis, find out the variation law and to be filled and corrected by software algorithm methods.This paper validates and improves the algorithm by analyzing the different factors affecting delay estimation accuracy. It gets a lot of practical data through repeated tests, and puts forward a series of corrections and improvements. In the end, it gets a good result. In addition, two forms of distribution stations were analyzed and compared, and conclude that linear cloth station has some advantages by taking simulation analysis in terms of anti-systemic disturbances. Then test and analysis the linear distribution station network and achieve accurate positioning cover the whole area.After a preliminary verification, this positioning system accuracy can be controlled within 100 meters range, provides a useful exploration for engineering practice.