Low-altitude Target Bearing-only Tracking With Signal Delay

Bearing-only tracking has been more and more widely used in military and civilian fields due to its good concealment,wide application range,and electromagnetic interference resistance.Among them,the technology of bearing-only tracking with signal delay has attracted wide attention for its ability to reduce the influence of signal propagation time on tracking results.The signal delay is usually caused by the propagation time of the signal.When the signal speed is much greater than the target speed,the signal delay can be ignored.When the signal speed is close to the target speed,the signal delay cannot be ignored.In the presence of clutter,the tracking performance of traditional bearing-only tracking algorithms considering signal delay is unsatisfactory due to the influence of clutter.Aiming at this problem,this thesis conducts research on bearing-only tracking algorithms considering signal delay.The main work of this thesis is as follows:1.Aiming at the bearing-only tracking problem with signal delay in clutter-free environment,this thesis proposes a Gaussian Sum Shifted Rayleigh Filter algorithm considering signal delay.Firstly,the signal emitting interval is estimated by using the time constraint relationship between the target and the sensor.Secondly,Gaussian Sum Shifted Rayleigh Filter is used for predicting the status of the target and forming a new extended measurement.Finally,the state of the target is updated with the extended measurement and Gaussian Sum Shifted Rayleigh Filter.Simulation shows that the proposed algorithm improves the estimation accuracy of position and signal emitting interval when signal delay needs to be considered.2.Aiming at the bearing-only tracking problem of single-sensor and single-target with signal delay in clutter environment,a Gaussian Sum Shifted Rayleigh Filter considering signal delay based on probabilistic data association algorithm is proposed.Firstly,validated measurements are obtained by constructing a tracking gate based on the Gaussian Sum Filter considering signal delay.Secondly,validated measurements are used to calculate the equivalent measurement and construct extended measurement.Finally,the target state and covariance are updated based on Gaussian Sum Shifted Rayleigh Filter and extended measurement.The simulation results show that the proposed algorithm can effectively reduce the impact of clutter and improve tracking accuracy in single-station and single-target scenarios with signal delay and clutter.3.Aiming at the bearing-only tracking problem of multi-station and multi-target in clutter environment with signal delay,a Gaussian Sum Shifted Rayleigh Filter algorithm considering signal delay based on a parallel structure joint data association algorithm is proposed.Firstly,a joint tracking gate is constructed based on the predicted state of the Gaussian Sum Filter considering signal delay to obtain the validated measurements.Secondly,a confirmation matrix and associated events are generated based on the valid measurements,and the associated probability is calculated to form the equivalent measurement and the extended measurement for each target.Finally,the state and covariance of each target are updated based on Gaussian Sum Shifted Rayleigh Filter and equivalent measurements.For multiple-sensor,the method of convex combination is adopted to address the track-to-track fusion problem.Simulation shows that the proposed algorithm effectively solves the data association problem of multi-station and multi-target with signal delay in cluttered environment,and can effectively estimate the signal emitting interval and target position.