Research On Interval Localization Algorithm Based On TDOA/FDOA

In order to meet the needs of war,target location and tracking technology comes into being and receives extensive research.In recent years,navigation and positioning systems have been applied to people’s livelihood,industry and other fields.Among the precise localization schemes based on various radio frequency signal parameters,the localization and tracking scheme based on time difference of arrival(TDOA)measurement and frequency difference of arrival(FDOA)measurement is a relatively common localization and tracking method due to its advantages of good concealment and low deployment cost.However,the location and velocity results obtained by traditional numerical computation frameworks do not contain deterministic information.In this context,this paper focuses on the localization and tracking calculation framework based on interval analysis,and estimates the location and velocity range of the target containing the real solution using prior information and TDOA/FDOA measurements.The concrete research contents are described as follows:(1)The calculation framework of interval hyperbolic localization based on interval TDOA is designed.This paper innovatively applies interval analysis to hyperbolic localization,proposes an interval hyperbolic localization algorithm,and estimates the interval results by using the iterative contraction strategy.This paper first determines the initial interval of the location based on the prior information and converts the TDOA measurement into the measurement interval.Aiming at the nonlinear problem of the localization model,the dichotomy is used to approach the two hyperbolic intervals of TDOA respectively,and the location estimation interval is obtained by taking the intersection of the two hyperbolic intervals according to the hyperbolic localization principle.Finally,the iterative process is called to shrink the location range until convergence.After simulation and analysis,the algorithm in this paper can not only reach the Cramér-Rao lower bound(CRLB),but also has superior certainty and remarkable reliability.In addition,this paper also analyzes the computational complexity of the proposed algorithm.(2)Further optimize the interval hyperbolic localization calculation framework.This paper proposes a coordinate system rotation scheme and a bidirectional iteration strategy to further improve the robustness and reliability of the interval hyperbolic localization calculation framework.The algorithm robustness problem refers to the problem that when the target is located in a closed area formed by three observation stations,if the angle between the line between the reference observation station and the auxiliary observation station and the Y axis of the established coordinate system is too small,evenly dividing the initial location interval by dividing the Y axis may lead to localization failure.To solve this problem,this article uses a linear rotation coordinate system to change the coordinates of the two auxiliary observation stations to adjust the angle between the observation station connecting line and the Y-axis,improving the localization success rate and robustness.In order to optimize the reliability of the algorithm results,this paper uses the bidirectional iterative characteristics of the interval algorithm to further shrink the measurement range width through backward contraction.Then,the position estimation interval is shrunk forward and iterated back and forth until convergence to obtain a smaller area of the position interval and improve the reliability of the algorithm.(3)Velocity interval estimation based on interval TDOA/FDOA.Based on interval analysis,this paper proposes an interval velocity estimation algorithm.After estimating the location interval of the target,the velocity interval of the target is estimated by the intersection of the two interval FDOA lines,and the iterative contraction process is used to reduce the estimated interval.For the processing of approaching the interval FDOA,the dichotomy or formula method are proposed.Among them,the formula method is to solve the corresponding X-axis velocity by directly bringing the assumed known Y-axis velocity into the FDOA formula.For the processing of the position variable in the FDOA formula,this paper proposes that it can be carried into the position estimation interval or the midpoint of the position estimation interval for calculation.A large number of simulation results show that the introduction of the midpoint method can effectively reduce the calculation cost while ensuring the reliable velocity estimation interval.