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Chen Q.,PLA University of Science and Technology | Chen Q.,Luoyang Electronic Equipment Testing Center | Chen B.,PLA University of Science and Technology | Shi L.,PLA University of Science and Technology | And 2 more authors.
Physics of Plasmas | Year: 2015

The Rayleigh-Taylor (R-T) instabilities are important hydrodynamics and magnetohydrodynamics (MHD) phenomena that are found in systems in high energy density physics and normal fluids. The formation and evolution of the R-T instability at channel boundary during back-flow of the lightning return stroke are analyzed using the linear perturbation theory and normal mode analysis methods, and the linear growth rate of the R-T instability in typical condition for lightning return stroke channel is obtained. Then, the R-T instability phenomena of lightning return stroke are simulated using a two-dimensional Eulerian finite volumes resistive radiation MHD code. The numerical results show that the evolution characteristics of the R-T instability in the early stage of back-flow are consistent with theoretical predictions obtained by linear analysis. The simulation also yields more evolution characteristics for the R-T instability beyond the linear theory. The results of this work apply to some observed features of the return stroke channel and further advance previous theoretical and experimental work. © 2015 AIP Publishing LLC. Source

Mo C.,Electronic Engineering Institution | Li J.,Electronic Engineering Institution | Dai H.,Luoyang Electronic Equipment Testing Center | Chen Q.,Electronic Engineering Institution | Zhao J.,Unit 95868 of PLA
Xitong Fangzhen Xuebao / Journal of System Simulation | Year: 2015

According to existed experimental evaluation of radar electronic jamming simulation for terminal guidance, the ballistic calculation model was simplified relatively. Particle model was usually adopted which made simulation results have serious distortion. The pulse Doppler radar seeker was discussed in six degree of freedom trajectory simulation of the closed loop (PDRS) for coherent video simulation, and simulation results show that the VGPO has no direct effect on the angle tracking loop, just through guidance filter affects the convergence angle velocity estimation, which leads to little change of guidance precision. The conclusion and anechoic chamber measurements results show that the PDRS of coherent video model for 6 degree of freedom closed-loop trajectory simulation is accurate, which provides an effective and practical solutions for parameters designing and performance evaluation of tactical cruise missile. ©, 2015, Editorial Office of Journal of System Simulation. All right reserved. Source

Xia B.,Luoyang Electronic Equipment Testing Center | Chen B.,Changchun University of Science and Technology
Proceedings of IEEE International Conference on Grey Systems and Intelligent Services, GSIS | Year: 2013

In order to solver the high frequency (HF) skywave signal field intensity data influenced by ionosphere fast fading, the gross error discriminant formula based on GM(1,1) is used to eliminate the break data influenced by the ionosphere fast fading in this paper. By introducing modeling accuracy and distinguish threshold, the gross error discriminant formula can rationally eliminate gross error data from signal field intensity data. For illustration, a typical HF skywave signal field intensity data treatment example is utilized to show the feasibility of the gross error discriminant formula in reducing the influence of ionosphere fast fading and improving the processing accuracy. Empirical results show that the Rayleigh distribution characteristic changes between, before and after treatment directly illustrated by the effectiveness of the gross error discriminant formula. The gross error discriminant formula based on the GM(1,1) Model can effectively eliminate the break data influenced by the ionosphere fast fading and solve the problem of HF skywave signal field intensity data processing and analysis. © 2013 IEEE. Source

Zhou W.,Luoyang Electronic Equipment Testing Center | Ruan R.,Zhengzhou University | Ruan R.,Xian Research Institute of Surveying and Mapping | Zhang H.,Zhengzhou University | Yao F.,Luoyang Electronic Equipment Testing Center
Lecture Notes in Electrical Engineering | Year: 2016

This paper reviews the history and evolution of the relative positioning based on the undifferenced (UD) observation. The internal mechanism of this method is explained by error division, that is, adopting the model of estimating quasi-clock parameter, which absorbs the unmodeled error of the receiver and the satellite to achieve the same effect of eliminating the common error explicitly by double differenced (DD) observation. With UD observation of Beidou Navigation Satellite System (BDS), various experiments are carried out to demonstrate the flexibility of the relative positioning mode presented, including network solution, static/kinematic baseline solution, and kinematic reference (kinematic for kinematic) solution. In the case of the experiment for network solution with baselines up to thousands of kilometers (2000–5000 km), precise post-processed orbit are used to cancel the influence of orbit errors, the repeatability within 1.1 cm in horizontal direction can be reached, the repeatability in vertical direction is less than 3 cm. The relative positioning precision of BDS on the condition of long baseline also needs to be improved because the phase center offset and variation of satellite antenna and receiver antenna have not been accurately calibrated, and there is still a gap of orbit precision between the current of BDS satellite and GPS. In the static baseline experiments, the broadcast ephemeris is adopted. For baseline of 800 m, the repeatability in horizontal and vertical are 3 and 8 mm, respectively, while for 30 km static baseline, they are 10 and 13 mm. In the experiments of kinematic baseline and kinematic reference solutions both horizontal and vertical precisions are in several centimeters; the latter is slightly worse because the coordinates of reference station are not accurate. © Springer Science+Business Media Singapore 2016. Source

Wang Y.,Luoyang Electronic Equipment Testing Center | Sun Z.,Luoyang Electronic Equipment Testing Center | Wang X.,Luoyang Electronic Equipment Testing Center
Journal of Geomatics | Year: 2015

This paper firstly introduces the theory of precise point positioning (PPP) and differential positioning briefly, then focuses on calculating the results of PPP and differential positioning with different ephemeris and clock correction by using WayPoint8.5 software, combining air dynamic GPS data of assignment of precision appraisal, and comparing the difference between the above results. The results show that the difference of the computed results between PPP and differential positioning is less than 80 cm. And we can not only compute the result of PPP using IGU ephemeris products, but also forecast the status of equipments for measurement and control. Source

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