This paper studies the dynamic estimation problem for multitarget tracking. A novel gat- ing strategy that is based on the measurement likelihood of the target state space is proposed to improve the overall effectiven...This paper studies the dynamic estimation problem for multitarget tracking. A novel gat- ing strategy that is based on the measurement likelihood of the target state space is proposed to improve the overall effectiveness of the probability hypothesis density （PHD） filter. Firstly, a measurement-driven mechanism based on this gating technique is designed to classify the measure- ments. In this mechanism, only the measurements for the existing targets are considered in the update step of the existing targets while the measurements of newborn targets are used for exploring newborn targets. Secondly, the gating strategy enables the development of a heuristic state estima- tion algorithm when sequential Monte Carlo （SMC） implementation of the PHD filter is investi- gated, where the measurements are used to drive the particle clustering within the space gate. The resulting PHD filter can achieve a more robust and accurate estimation of the existing targets by reducing the interference from clutter. Moreover, the target birth intensity can be adaptive to detect newborn targets, which is in accordance with the birth measurements. Simulation results demonstrate the computational efficiency and tracking performance of the proposed algorithm.展开更多
Visual object tracking has been drawing increasing attention in recent years,as a fundamental task in computer vision.To extend the range of tracking applications,researchers have been introducing information from mul...Visual object tracking has been drawing increasing attention in recent years,as a fundamental task in computer vision.To extend the range of tracking applications,researchers have been introducing information from multiple modalities to handle specific scenes,with promising research prospects for emerging methods and benchmarks.To provide a thorough review of multi-modal tracking,different aspects of multi-modal tracking algorithms are summarized under a unified taxonomy,with specific focus on visibledepth(RGB-D)and visible-thermal(RGB-T)tracking.Subsequently,a detailed description of the related benchmarks and challenges is provided.Extensive experiments were conducted to analyze the effectiveness of trackers on five datasets:PTB,VOT19-RGBD,GTOT,RGBT234,and VOT19-RGBT.Finally,various future directions,including model design and dataset construction,are discussed from different perspectives for further research.展开更多
The divergence angle of laser beam used in space laser communication is usually no more than 100μrad.Using laser beam with small divergence angle to achieve acquisition and tracking for space laser link has always be...The divergence angle of laser beam used in space laser communication is usually no more than 100μrad.Using laser beam with small divergence angle to achieve acquisition and tracking for space laser link has always been a difficult problem.In addition,the random nature of the atmosphere will affect the satellite-ground laser link,which increases the difficulty of the acquisition and stable tracking for the laser link.Thus,taking into account the above challenges for satellite-ground laser communication,an acquisition and tracking scheme of using both beacon beam and signal beam was designed for the Laser Communication Terminal(LCT)of Shijian 20 satellite.In-orbit test results indicated that under the condition of moderate atmospheric turbulence(atmospheric coherence length r0≈3 cm),the process of acquisition and tracking for the satellite-ground laser link can be completed within 1 s after the initial pointing between the LCT and Optical Ground Station(OGS)is performed,and the tracking error was less than 1μrad(3σ).In addition,the laser link can be re-established quickly once being interrupted by unsteady atmospheric turbulence,and can be maintained for a long time under moderate twurbulence conditions,which lays a foundation for future application of satellite-ground laser communication.展开更多
基金supported by the Aeronautical Science Foundation of China(No.201401P6001)
文摘This paper studies the dynamic estimation problem for multitarget tracking. A novel gat- ing strategy that is based on the measurement likelihood of the target state space is proposed to improve the overall effectiveness of the probability hypothesis density （PHD） filter. Firstly, a measurement-driven mechanism based on this gating technique is designed to classify the measure- ments. In this mechanism, only the measurements for the existing targets are considered in the update step of the existing targets while the measurements of newborn targets are used for exploring newborn targets. Secondly, the gating strategy enables the development of a heuristic state estima- tion algorithm when sequential Monte Carlo （SMC） implementation of the PHD filter is investi- gated, where the measurements are used to drive the particle clustering within the space gate. The resulting PHD filter can achieve a more robust and accurate estimation of the existing targets by reducing the interference from clutter. Moreover, the target birth intensity can be adaptive to detect newborn targets, which is in accordance with the birth measurements. Simulation results demonstrate the computational efficiency and tracking performance of the proposed algorithm.
基金supported in part by National Natural Science Foundation of China(Nos.U23A20384 and 62022021)in part by Joint Fund of Ministry of Education for Equipment Pre-research(No.8091B032155)+1 种基金in part by the National Defense Basic Scientific Research Program(No.WDZC20215250205)in part by Central Guidance on Local Science and Technology Development Fund of Liaoning Province(No.2022JH6/100100026).
文摘Visual object tracking has been drawing increasing attention in recent years,as a fundamental task in computer vision.To extend the range of tracking applications,researchers have been introducing information from multiple modalities to handle specific scenes,with promising research prospects for emerging methods and benchmarks.To provide a thorough review of multi-modal tracking,different aspects of multi-modal tracking algorithms are summarized under a unified taxonomy,with specific focus on visibledepth(RGB-D)and visible-thermal(RGB-T)tracking.Subsequently,a detailed description of the related benchmarks and challenges is provided.Extensive experiments were conducted to analyze the effectiveness of trackers on five datasets:PTB,VOT19-RGBD,GTOT,RGBT234,and VOT19-RGBT.Finally,various future directions,including model design and dataset construction,are discussed from different perspectives for further research.
文摘The divergence angle of laser beam used in space laser communication is usually no more than 100μrad.Using laser beam with small divergence angle to achieve acquisition and tracking for space laser link has always been a difficult problem.In addition,the random nature of the atmosphere will affect the satellite-ground laser link,which increases the difficulty of the acquisition and stable tracking for the laser link.Thus,taking into account the above challenges for satellite-ground laser communication,an acquisition and tracking scheme of using both beacon beam and signal beam was designed for the Laser Communication Terminal(LCT)of Shijian 20 satellite.In-orbit test results indicated that under the condition of moderate atmospheric turbulence(atmospheric coherence length r0≈3 cm),the process of acquisition and tracking for the satellite-ground laser link can be completed within 1 s after the initial pointing between the LCT and Optical Ground Station(OGS)is performed,and the tracking error was less than 1μrad(3σ).In addition,the laser link can be re-established quickly once being interrupted by unsteady atmospheric turbulence,and can be maintained for a long time under moderate twurbulence conditions,which lays a foundation for future application of satellite-ground laser communication.
