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3rd IEEE International Conference on Data science in Cyberspace, DSC 2018

作者： Yang, Fande Qiang, Li Science and Technology on Complex Electronic System Simulation Laboatory Space Engineering University Beijing China

ISBN: (纸本)9781538642108

The misunderstanding of situation system developers and users leads to the low efficiency of the technology to apply. With three perspectives of cognition as systematicness, subjectivity and interactivity, the functions and coupling relationships of the components of situational cognition system are studied. The interaction between the cognitive subjects and the situation servers is focused on. The generation framework of situation visualization service is proposed, and the cognition demands and application orientation of each link are analyzed. The service mode of situation visualization is discussed. It provides channels for situation processing and visualization technologies to be applied effectively, and for situational data to be used efficiently. © 2018 IEEE.

关键词： Visualization

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An Improved Frequency Tracking Algorithm for Frequency Hopping Signals Based on ARMA Model

An Improved Frequency Tracking Algorithm for Frequency Hoppi...

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IEEE International Conference on Signal Processing, Communications and Computing

作者： Jing Ma Bin Shi Yifan Wang Xiaochen Guo Science and Technology on Special System Simulation Laboratory Information and Communication Engineering Department Harbin Engineering University

ISBN: (纸本)9781728117096

Aiming at the real-time processing problem of frequency hopping signals, a frequency tracking algorithm based on FFT, multi-channel clustering and the autoregressive moving average (ARMA) model is proposed in this paper. First, the algorithm performs FFT processing on the received signal samples and estimates the number of source signals and carrier frequency by clustering method. Second, estimate the model coefficients to construct the ARMA model. Then, predict the signal and estimate the decision threshold. Finally, the frequency hopping is determined according to the error between the predicted value of the signal sample and the true value. The experimental results show that the improved algorithm has higher frequency estimation accuracy than the traditional ARMA algorithm after receiving enough signal samples and has lower computational complexity than the SBL algorithm.

关键词： Frequency hopping signals Multi-channel clustering Autoregressive moving average model Frequency hopping signal sampling frequency tracking signals algorithms Frequency estimation predicted value Clustering methods Fast Fourier transform

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Researchment of Mainlobe Anti-jamming Algorithms

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Journal of Physics: Conference Series 2020年第1期1673卷

作者： Zhangkai Luo Zhongmin Pei Yinan Li Xinmin Wang Bo Zou Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University Beijing 101400 China.

Main lobe interferences usually cause the distortion and peak offset of main lobe and the heighten of side lobe level in adaptive beamformers. The block matrix algorithm utilized the direction vector which was determined by both the antenna arrays and the direction of interference to eliminate the main lobe interference. But this algorithms is sensitive to the error occurred in the interference arrive angle and would consume the array of degrees of freedom. In this paper a new algorithm is proposed which projects the receive signal into a space which is orthogonal to the signal subspace to achieve the goal. The space can get by three steps. Frist we obtain eigenvalues by the decomposition of the covariance matrix of the snapshots to evaluate the noise power. Then we get a new matrix by removing the noise from the covariance matrix of the snapshots. At last we get the target space by conducting the singular value decomposition to the new matrix. Performance is mainly assessed in terms of the beamforming gain and the signal to interference and noise (SINR) ratio. The computer simulation shows the effective of this method.

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Modified ddpg algorithm applied to simulation supervised learning 48

Modified ddpg algorithm applied to simulation supervised lea...

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48th International Conference on Computers and Industrial Engineering, CIE 2018

作者： Jia, Zhengxuan Xiao, Yingying Zhao, Zhilong Lin, Tingyu State Key Laboratory of Intelligent Manufacturing System Technology Beijing Institute of Electronic System Engineering Beijing China Beijing Complex Product Advanced Manufacturing Engineering Research Center Beijing Simulation Center Beijing China Science and Technology on Space System Simulation Laboratory Beijing Simulation Center Beijing China

With rapid development of machine learning, supervised learning and reinforcement learning have witnessed a considerable success. However, some problems like the absence of supervising signal in supervised learning are not yet solved. In this paper, a novel approach has been proposed based on the deep deterministic policy gradient algorithm to address such kind of problems, forming the training of an agent supervised by the simulation environment. As verification, our proposed approach is applied to a modified tower defense game, and the experimental results confirmed the effectiveness of our proposed approach. © 2018, Curran Associates Inc. All rights reserved.

关键词： Supervised learning

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Polybaric differentiation for arc magma genesis: a perspective from alumina saturation index

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Lithos 2025年 512-513卷

作者： Peng Gao Marcos García-Arias William J. Collins Long Chen Hua Xiang Hai-Ou Gu Zi-Fu Zhao State Key Laboratory of Lithospheric and Environmental Coevolution University of Science and Technology of China Hefei 230026 China Deep Space Exploration Laboratory/School of Earth and Space Sciences USTC Hefei 230026 China Departamento de Geología Universidad de Salamanca Salamanca Spain School of Earth and Planetary Sciences Curtin University Perth Western Australia 6845 Australia Frontiers Science Center for Deep Ocean Multispheres and Earth System Key Lab of Submarine Geosciences and Prospecting Techniques Ministry of Education and College of Marine Geosciences Ocean University of China Qingdao 266100 China Laboratory for Marine Mineral Resources Qingdao Marine Science and Technology Center Qingdao 266237 China Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China School of Resources and Environmental Engineering Hefei University of Technology Hefei 230009 China

The crustal level at which arc magma differentiation predominantly occurs remains a subject of debate. Experimental petrology has demonstrated that the SiO 2 -ASI (alumina saturation index) relationship of arc magmas could address this issue because it strongly depends on pressure, but these results are far from conclusive due to either insufficient evaluation or inconsistency with geological observations. Using compiled data from arc volcanics and crystallization experiments, this study classifies the arcs as thick (40–63 km), normal (25–35 km) and thin (15–20 km) according to crustal thickness. We find that experimental melts produced at the corresponding arc root pressures can only account for the most aluminous compositions at intermediate SiO 2 content (55–65 wt%), with the typical lesser aluminous compositions requiring lower pressure crystallization. To further evaluate the pressure at which crystallization in arcs occurs, phase equilibrium modeling is used here to model the crystallization processes from primitive arc rocks on different modes (isobaric and polybaric, equilibrium and fractional) in the range of 1.5 to 0.2 GPa. Modeled results verify the experimental findings and highlight that the liquid lines of descent (LLD) from 0.2 GPa overlap the lesser aluminous parts of the SiO 2 -ASI plots for arc rocks. LLD from H 2 O-poor systems are deviated to lower ASI at constant SiO 2 relative to the H 2 O-rich ones due to more proportion of plagioclase in the H 2 O-poor condition. The dominant phase to increase melt ASI is clinopyroxene, whereas garnet at high-pressure and plagioclase at low-pressure (especially H 2 O-poor) play an opposite role. This study underscores that polybaric differentiation is more relevant to the genesis of arc volcanics than deep crustal differentiation, irrespective of crustal thickness.

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Fusion of panchromatic and multispectral images via morphological operator and improved PCNN in mixed multiscale domain 10

Fusion of panchromatic and multispectral images via morpholo...

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10th IAPR Workshop on Pattern Recognition in Remote Sensing, PRRS 2018

作者： Jiao, Jiao Lingda, Wu Department of Graduate Management Space Engineering University Beijing China Simulation Laboratory Space Engineering University Science and Technology on Complex Electronic System Beijing China

ISBN: (纸本)9781538684795

In order to effectively combine the spectral information of the multispectral (MS) image with the spatial details of the panchromatic (PAN) image and improve the fusion quality, a fusion method based on morphological operator and improved pulse coupled neural network (PCNN) in mixed multi-scale (MM) domain is proposed. Firstly, the MS and PAN images are decomposed by nonsubsampled shearlet transform (NSST) to low- and high-frequency coefficients, respectively;secondly, morphological filter-based intensity modulation (MFIM) technology and stationary wavelet transform (SWT) are applied to the fusion of the low-frequency coefficients;an improved PCNN model is employed to the fusion of the high-frequency coefficients;thirdly, the final coefficients are reconstructed with inverse NSST. The experimental results on QuickBird satellite demonstrate that the proposed method is superior to five other kinds of traditional and popular methods: HIS, PCA, SWT, NSCT-PCNN and NSST-PCNN. The proposed method can improve the spatial resolution effectively while maintaining the spectral information well. The experimental results show that the proposed method outperforms the other methods in visual effect and objective evaluations. © 2018 IEEE.

关键词： Image fusion

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Global Microwave Land Surface Emissivity Under all Weather Conditions Derived From Fengyun-3D Satellite Observations

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Journal of Geophysical Research: Atmospheres 2025年第11期130卷

作者： Qingyang Liu Jiheng Hu Peng Zhang Yonghong Liu Rui Li School of Earth and Space Sciences CMA-USTC Laboratory of Fengyun Remote Sensing University of Science and Technology of China Hefei China Department of Climate and Space Sciences and Engineering University of Michigan Ann Arbor Michigan USA Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites China Meteorological Administration (LRCVES/CMA) National Satellite Meteorological Center China Meteorological Administration Beijing China CMA Earth System Modeling and Prediction Centre (CEMC) China Meteorological Administration Beijing China

A global microwave land surface emissivity (MLSE) data set from January 2020 to December 2022 under all-weather conditions was retrieved using microwave brightness temperatures from Fengyun-3D Microwave Radiation Imager (MWRI), combined with cloud properties derived from the Medium Resolution Spectral Imager on the same satellite. The contributions of clouds and atmospheric particles were calculated using a four-stream microwave radiative transfer model and subtracted from the Tbs measured at the top of the atmosphere. To evaluate the MWRI MLSE, we compared it with four reference clear-sky emissivity data sets retrieved from Global Precipitation Mission Microwave Imager, Advanced Microwave Scanning Radiometer for EOS (AMSR-E), and the Tool to Estimate Land Surface Emissivity at Microwaves and Millimeter waves (TELSEM) which is based on the measurements of Special Sensor Microwave/Imager (SSM/I). We also assessed the sensitivity of seasonal variations of MLSE to surface conditions indicated by the normalized difference vegetation index and precipitation seasonal cycles. Results demonstrate that our retrieval achieves good consistencies with the four reference products, exhibiting similar surface characteristics and spectral dependencies. Based on the all-weather retrievals, we studied the potential impacts of clouds on MLSE in tropical regions. Results indicate that the presence of clouds may lead to a decrease in land surface emissivity due to potentially increased moisture in the soil-vegetation mediums. The first global all-weather emissivity product of Chinese Fengyun-3D MWRI All-weather retrieval using Fengyun-3D Medium Resolution Spectral Imager (MERSI) cloud properties Global evaluations with five reference emissivity data sets of various techniques Numerical weather prediction models use microwave land surface emissivity (MLSE) to improve forward simulation accuracy through satellite data assimilation. In this study, we utilized measurements from the Fengyun-

关键词： microwave emissivity fengyun-3D all-weather MWRI MERSI passive microwave remote sensing

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Approaching the Fundamental Limit of Orbital-Angular-Momentum Multiplexing Through a Hologram Metasurface

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Physical Review Applied 2021年第6期16卷 064042-064042页

作者： Shuai S.A. Yuan Jie Wu Menglin L.N. Chen Zhihao Lan Liang Zhang Sheng Sun Zhixiang Huang Xiaoming Chen Shilie Zheng Li Jun Jiang Xianmin Zhang Wei E.I. Sha College of Information Science and Electronic Engineering Zhejiang University Hangzhou 310027 China Department of Education of Anhui Province Ministry of Education and the Key Laboratory of Electromagnetic Environmental Sensing Anhui University Hefei 230039 China Department of Electrical and Electronic Engineering The University of Hong Kong Hong Kong Department of Electronic and Electrical Engineering University College London Torrington Place London WC1E 7JE United Kingdom Anhui Province Key Laboratory of Simulation and Design for Electronic Information System Hefei Normal University Hefei 230601 China School of Electronic Science and Engineering University of Electronic Science and Technology of China Chengdu 611731 China School of Information and Communications Engineering Xi’an Jiaotong University Xi’an 710049 China

Establishing and approaching the fundamental limit of orbital-angular-momentum (OAM) multiplexing are necessary and increasingly urgent for current multiple-input multiple-output research. In this work, we elaborate the fundamental limit in terms of independent scattering channels (or the degrees of freedom of scattered fields) through angular-spectral analysis, in conjunction with a rigorous Green’s function method. The scattering-channel limit is universal for arbitrary spatial-mode multiplexing, which is launched by a planar electromagnetic device, such as antenna, metasurface, etc., with a predefined physical size. As a proof of concept, we demonstrate both theoretically and experimentally the limit by a phase-only metasurface hologram that transforms orthogonal OAM modes to plane-wave modes scattered at critically separated angular-spectral regions. Particularly, a minimax optimization algorithm is applied to suppress angular-spectrum aliasing, achieving good performances in both full-wave simulation and experimental measurement at microwave frequencies. This work offers a theoretical upper bound and corresponding approach route for engineering designs of OAM multiplexing.

关键词： Angular momentum of light Polarization of light Spatial profiles of optical beams Devices Metamaterials Surfaces Holography Light scattering

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A Comparative Evaluation of AutoEncoder-Based Unsupervised Anomaly Detection Methods Applied on space Payload 6

A Comparative Evaluation of AutoEncoder-Based Unsupervised A...

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6th International Conference on Dependable systems and Their Applications, DSA 2019

作者： Du, Junrong Song, Lei Zheng, Taisheng Guo, Lili Ma, Chao University of Chinese Academy of Sciences Key Laboratory ofSpace Utilization Technology and Engineering Center Space Utilization Chinese Academy of Sciences Beijing China Key Laboratory ofSpace Utilization Technology and Engineering Center Space Utilization Chinese Academy of Sciences Beijing China Beijing key Laboratory of Measurement and Control of Mechanical and Electrical System Beijing Information Science and Technology University Beijing China

ISBN: (纸本)9781728160573

The anomaly detection technology is the basis for ensuring the safe and stable operation of the on-rail payload. The traditional threshold-based anomaly detection method has low accuracy and poor flexibility, and cannot detect abnormalities in real time. In addition, due to the lack of abnormal samples, the distribution of positive and negative samples is extremely imbalanced, which increases the difficulty of abnormal detection. Therefore, this paper proposes an unsupervised learning method based on AutoEncoder and its variants, the Basic AutoEncoder, Deep AutoEncoder and Sparse AutoEncoder are used to verify the algorithm on three public datasets. And using the above three algorithms to carry out the case application on the real load dataset. The experiments show whether in the public dataset or the real data of the payload, the three methods of AutoEncoder have achieved good results, proving the AutoEncoder and its variants have a good application in anomaly detection. At the same time, it is verified that the three algorithms have different effects on different datasets, which proves that the AutoEncoder with different characteristics need to be selected in different scenarios. © 2020 IEEE.

关键词： Anomaly detection

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A location method for ground moving target with azimuth spectrum aliasing in Geosynchronous spaceborne-Airborne Bistatic multichannel SAR

A location method for ground moving target with azimuth spec...

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Signal, Information and Data Processing (ICSIDP), IEEE International Conference on

作者： Ying Zhang Wei Xiong Xichao Dong Cheng Hu Chengxiang Liu Yang Sun Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University Beijing China Key Laboratory of Electronic and Information Technology in Satellite Navigation (Beijing Institute of Technology) Ministry of Education Beijing China

ISBN: (数字)9781728123455

ISBN: (纸本)9781728123462

Geosynchronous spaceborne-Airborne Bistatic multichannel SAR (GEO-SABM SAR) maintains the fine temporal sampling and wide coverage characteristics of monostatic GEO SAR. But due to the PRF of GEO platform is very low, azimuth spectrum aliasing (ASA) will occur in GEO-SABM SAR which will make a moving target divided into several sub-targets. In this paper, a location method for ground moving target with ASA has given. From the simulation results, the moving target can be discriminated and located.

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