Target In Near Space Research Articles

A tracking algorithm of hypersonic target based on dynamic model and square-root cubature Kalman filter

Because of the complexities of target motion features, the tracking of hypersonic target in near space is difficult. In this paper, a new adaptive tracking algorithm based on dynamic model and improved square-root cubature Kalman filter(SRCKF) is proposed. According to the target movement characteristics, the improved adaptive piecewise constant Jerk model is proposed based on the dynamic model. The improved square-root cubature Kalman filter which the model mismatch detection function is introduced to reduce the state estimation error. The simulation results indicate that the proposed method which combines the model and the estimation algorithm has higher accuracy and stability on maneuvering target tracking than other existing methods. The research provides a feasible solution to the further improvement of the real time tracking accuracy of near-space hypersonic target.

Inversion of Position for Low Speed Target in Near Space Using Non-resolved Photometric and Astrometric Data

A method for estimating the position parameters of a low speed target (LST) in near space was presented. The estimation method utilizes apparent magnitude, azimuthal angle, and angle of elevation to invert the position of a typical LST, such as a high altitude balloon (HAB). A photometric observation model composed of specular and diffuse reflection components for the LST was established. An astrometric observation model was discussed to deduce the azimuth and elevation of a ground-based opto-electronic detection system for the LST. An extended Kalman filter (EKF) was designed to invert the state parameters of the position and velocity of the LST from photometric and astrometric data. Two sets of simulations were carried out to validate this inversion method. The simulation results show that the simulation errors for the estimated parameters are small, the estimated positions agree with GPS very well, and the non-resolved photometric and angular data can be used to estimate the indirect observable position state parameters for a LST in near space.

Hypersonic sliding target tracking in near space

To improve the tracking accuracy of hypersonic sliding target in near space, the influence of target hypersonic movement on radar detection and tracking is analyzed, and an IMM tracking algorithm is proposed based on radial velocity compensating and cancellation processing of high dynamic biases under the earth centered earth fixed (ECEF) coordinate. Based on the analysis of effect of target hypersonic movement, a measurement model is constructed to reduce the filter divergence which is caused by the model mismatch. The high dynamic biases due to the target hypersonic movement are approximately compensated through radial velocity estimation to achieve the hypersonic target tracking at low systematic biases in near space. The high dynamic biases are further eliminated by the cancellation processing of different radars, in which the track association problem can be solved when the dynamic biases are low. An IMM algorithm based on constant acceleration (CA), constant turning (CT) and Singer models is used to achieve the hypersonic sliding target tracking in near space. Simulation results show that the target tracking in near space can be achieved more effectively by using the proposed algorithm.

Modeling and Simulation of the Optical Properties of Low-Speed Target in Near Space

A novel near space target optical properties modeling method based on the reverse Monte Carlo optical tracking is proposed. Both the environment characteristics in near space and the light transmission characteristics in different detection platform mode are considered and analysis in detail. The invalid light can be eliminated adaptively in this model. According to the phase relationship of target-observing systems-the sun, the optical properties of the target can be obtained. Some numerical simulations are made to test the accuracy and capability of the proposed modeling method.

Evaluation for the Hypersonic Near-Space Target Threat Based on GRA-TOPSIS Model

From the need of antagonising the hypersonic near-space target (HNST), a multi-attribute evaluation method of HNST threat based on RAG-TOPSIS is proposed; the target attribute weights are dealt with using RAG; the grey state for people to understand the selection of attributes in the traditional TOPSIS is avoided and the confirming of the weights of target attributes is more scientific. The multi-attribute evaluation model of HNST’s threat is established, then the rationality and effectiveness of the method is verified by an example.