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Yuan H.,Chinese Academy of Sciences | Yuan H.,University of Chinese Academy of Sciences | Yuan H.,Artillery Academy of Peoples Liberation Army | Mei H.,Chinese Academy of Sciences | And 2 more authors.
Guangxue Xuebao/Acta Optica Sinica | Year: 2011

Considering the influences of atmospheric refraction on the satellite laser ranging, an algorithm for calculating the optical path differences based on ray tracing is studied. Firstly, the annual mean atmospheric refractivity modulus height profiles of 46 typical regions in China are fitted by using meteorological sounding datum and high level model datum synthetically. Secondly, the results calculated by the Marini-Murray model and ray tracing which is based on the monthly average model and the annual mean model are compared and analyzed. Then, the national distribution of the optical path difference of satellite laser ranging is presented. Finally, the relations between the optical path difference with the height above sea level of ranging site and the elevation of satellite are numerically investigated.

Wang B.,National University of Defense Technology | An W.,National University of Defense Technology | Xie K.,Artillery Academy of Peoples Liberation Army | Zhou Y.,National University of Defense Technology
Hangkong Xuebao/Acta Aeronautica et Astronautica Sinica | Year: 2010

To deal with the problem of sensor resource scheduling for continual multi-object tracking with low earth orbit constellation, the object tracking tasks are first classified into two sets, i.e., the higher precision task set and the lower precision task set, and their state transition procedures are analyzed. Then, a sensor scheduling model for each task set is established based on the dynamic priority theory. Furthermore, a novel real-time sensor scheduling algorithm based on a multi-model is proposed. Simulations executed in diverse scenarios indicate that the applicability of the proposed algorithm exceeds that of the traditional methods which consider the dilution of precision as the optimal objective or threshold constraint. This is especially true in the case of multi-object scenarios of centralized distribution. The drop-out ratio of the proposed method is greatly reduced as compared with that of the traditional methods, although a few objects show slightly larger tracking errors.

Wang J.-D.,South China Normal University | Wei Z.-J.,South China Normal University | Zhang H.,Artillery Academy of Peoples Liberation Army | Qin X.-J.,Guangzhou University | And 4 more authors.
Journal of Physics B: Atomic, Molecular and Optical Physics | Year: 2010

We propose a scheme for quantum key distribution, in which single photons are encoded with polarization states and then divided and delayed to encode phase differences between two sequential pulses. In an example, the BB84 and DPS (differential phase shift) protocols are combined to achieve single-photon two-qubit quantum key distribution. This scheme can increase the key generation efficiency up to 7/6, higher than that of the conventional single-photon one-qubit quantum key distribution scheme. © 2010 IOP Publishing Ltd.

Lin L.,National University of Defense Technology | Lin L.,94810th Unit of Peoples Liberation Army | Xu H.,National University of Defense Technology | Long Y.,National University of Defense Technology | And 2 more authors.
Guangxue Xuebao/Acta Optica Sinica | Year: 2011

The essentiality of cluster tracking for midcourse ballistic target group by low earth orbit(LEO) optical constellation is analyzed. And an improved method of cluster tracking is presented. The probability hypothesis density filter is used to track multi-target on the focal plane, filter out clutter, and estimate target number and state. Then for improving the stability of focal plane target tracking, an image registration method is adopted to adjust interframes target state estimation. Finally, the focal plane 2D centroid measurement of target group is computed based on the focal plane tracking results, and unscented Kalman filter(UKF) is adopted to track the 3D centroid of target group through multi-sensor fusion in sequence. Simulation results show that, the proposed method works well under different clutter rates, and gains a better precision than the traditional one. Meanwhile, it successfully realizes the tracking of each target on the space-based infrared focal plane.

Wang G.,CAS Anhui Institute of Optics and Fine Mechanics | Wang G.,Artillery Academy of Peoples Liberation Army | Sun D.,Anhui University of Science and Technology | Duan L.,Artillery Academy of Peoples Liberation Army | Shu Z.,CAS Anhui Institute of Optics and Fine Mechanics
Guangxue Xuebao/Acta Optica Sinica | Year: 2011

Fabry-Pérot etalon is usually employed as discriminating frequency unit in direct detection Doppler wind lidar, and performance of Fabry-Pérot etalon and design of state of incident light beam are important factors in measurement error of the whole systems. The fundamental theory of the Doppler wind lidar based on a triple Fabry-Pérot etalon is introduced. After deep analysis of free spectral range (FSR) and full width at half maximum (FWHM) and peak value interval in two edge channels, the project of parameters design is obtained. The state of incident light beam has an obvious effect on transmission curve of Fabry-Pérot etalon. According to the correlative equation, the effects of incident angle, divergence angle and partial facula permeating through etalon channel designed on transmission curve are provided, and corresponding measurement error is calculated and simulated.

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