Wuhan, China
Wuhan, China

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Liu S.H.,AFEWA | Hu Z.M.,Huangpi Noncommissioned Officer Academy | Tang Y.W.,Unit 94878
Applied Mechanics and Materials | Year: 2013

The principle of imaging method based on matched filtering and chaos theory are introduced. On this basis, a new method of range imaging using the correlation function of the chaotic signal is provided. At the same time, simulation models and simulation results are given. The experiment results show this method has the advantages of good range resolution and excellent anti-interference performance, the quality of the reconstruction image is fine. © (2013) Trans Tech Publications, Switzerland.


Zhang X.H.,AFEWA | Sheng W.,AFEWA | Liu S.H.,AFEWA
Applied Mechanics and Materials | Year: 2013

The prediction of chaotic time sequence based on AR model is studied. The forming mechanism of the first-order Bragg lines of sea clutter is analyzed. According to the signal characteristic of sea clutter, a sea clutter time sequence predictor and a skywave radar sea clutter suppression system based on AR model are presented. The cancelling of sea clutter is achieved by subtracting the predicted signal from the original signal. The simulation results show that the first-order Bragg lines in the signal were suppressed effectively after processed by this sea clutter suppression system, the detecting performance of skywave radar was increased dominatively. © (2013) Trans Tech Publications, Switzerland.


Liu S.,AFEWA | Li D.,AFEWA | Hu B.,AFEWA
Lecture Notes in Electrical Engineering | Year: 2016

Based on the ballistic missile detection characteristics of the skywave OTHR system, a ballistic missile detection performance method for the skywave OTHR is presented based on the preliminary index and the weighted index. The detection performance index is divided into the preliminary index and the weighted index. For the preliminary index, the performance quantization value is computed by a binary function. For the weighted index, a detection performance index system is constructed, and the performance quantization value of the index system is calculated according to the cloud gravity center theory. Based on the performance quantization values of the preliminary index and the weighted index, the ballistic missile detection performance is evaluated using the cloud remark assembly. Finally, the feasibility of this method is verified through a calculated example. © Springer-Verlag Berlin Heidelberg 2016.


Xiao S.,Group of Graduate Management | Li Z.-H.,Group of Graduate Management | Tan X.-S.,AFEWA | Wang H.,AFEWA
Dandao Xuebao/Journal of Ballistics | Year: 2013

The traditional tracking algorithms can not track near-space hypersonic-vehicle (NSHV) effectively. Aiming at this problem, one kind of variable-structure multiple-model tracking algorithm (DG-VSMM) based on the directed graph was proposed. The problem that the model set of traditional variable structure multiple-model algorithm (VSMM) can not quickly jump was analyzed, and the acceleration and angular velocity were selected as the model parameters, and the directed graph of model was built. According to the target maneuver situation, the model subset having a hand in the calculation was chosen, and the local model subset was adjusted for real-time based on the posterior probability of model to realize variable-structure multiple-model tracking. The Monte-Carlo simulation results show that this method can realize the quick jump among model subsets, and the tracking precision, stability and computation are improved, and it can be applied in near-space hypersonic-vehicle tracking.


Zhan L.,AFEWA
IET Conference Publications | Year: 2013

Range walk of the fourth generation fighters echo for traditional radar signal processing is a serious problem in the long coherent integration time. To solve the problem, a novel coherent Radon transform based weak target detection algorithm for metric-band phased array radar is proposed. First the echo signal model of supersonic weak target is provided, and the characteristic of range walk is analyzed. Based on this, the coherent Radon transform based long term coherent integration algorithm along the range walk line is presented. Finally, the performance of target detection and parameter estimation of the algorithm are analyzed by the simulation experiments, which suggest that the proposed algorithm has better detection performance compared with Hough transform method and MTD method.


Liu S.,AFEWA | Sheng W.,AFEWA | Zhang X.,AFEWA
Proceedings - 2013 5th Conference on Measuring Technology and Mechatronics Automation, ICMTMA 2013 | Year: 2013

An evaluation scheme of the coverage of the sky wave radar is researched. On the basis of seventeen kinds of indexes of the sky wave radar coverage, a sort of model of coverage quantitative evaluation with three levels of hiberarchy is established by means of the modified analytical hierarchy process(AHP) based on grey relational grade(GRG), the quantitative calculation method of all level indexes is discussed, and the effectiveness of the model is verified. This method solve the problem in AHP effectively. The result shows that the evaluation scheme of sky wave radar coverage is feasibility. © 2013 IEEE.


Zhang Y.,AFEWA | Huang X.,AFEWA
2013 IEEE 3rd International Conference on Information Science and Technology, ICIST 2013 | Year: 2013

It is a difficult problem to denoise the function optical imaging datum under low Signal Noise Ratio (SNR). The traditional method is filtering denoising. As the noise is wide-band, there remains strong noise in the filtering signal. To resolve this problem, the signal and the noise are regarded as different independent sources, and the independent component analysis (ICA) method is used to separate these independent sources. With the prior information of the signal, we can extract it from the independent sources, so the noise can be sharply reduced. The simulation results show that the ICA denoising performance is obviously superior to the filtering under low SNR. © 2013 IEEE.


Liu S.H.,AFEWA | Sheng W.,AFEWA | Zhang X.H.,AFEWA
Applied Mechanics and Materials | Year: 2013

An evaluation scheme of skywave radar coverage of ship target is researched. On the basis of fifteen kinds of indexes of the skywave radar coverage, a sort of model of coverage quantitative evaluation with three levels of hiberarchy is established by means of the modified analytical hierarchy process(AHP) based on grey relational grade(GRG), the quantitative calculation method of all level indexes is discussed, and the effectiveness ofthe model is verified. This method solve the problem in AHP effectively. The result shows that the evaluation scheme of skywave radar coverage is feasibility. © (2013) Trans Tech Publications, Switzerland.


Zhai Q.,AFEWA | Li Y.,AFEWA
Applied Mechanics and Materials | Year: 2014

With the development of computer technology, programmable logic controller (PLC) is becoming more powerful and more convenient to be used. However, if the working condition of PLC is too harsh, such as high temperature, humidity, vibration, strong shock and electromagnetic interference, it will directly affect the normal, safe and reliable operation of the whole automatic control system. And coupled with the ineffective peripheral circuit interference measures, it greatly reduced the reliability of the automatic control system and even leads to failure. Therefore, the design of industrial PLC automatic control system must give top priority to the reliability of the hardware and software aspects. This paper introduces the concept and existing research of PLC –based automatic control system, and discusses about the specific design studies from both hardware and software aspects. © (2014) Trans Tech Publications, Switzerland.


Liu S.H.,AFEWA | Bi Z.J.,AFEWA | Zhang W.,AFEWA
Applied Mechanics and Materials | Year: 2013

In order to overcome the difficulty of modern radar fault prediction, which induced by the complexity of system compose, fuzziness of configuration connection and incompletely and uncertainty of character parameters, a LM-BP neural networ model is studied based on BP neural networ model and LM optimized algorithm to optimize the network error function and increase the prediction precision of this model. The simulation and analysis are finished using a radar fault prediction example and show validity the of this model. © (2013) Trans Tech Publications, Switzerland.

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