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Impact of Atmospheric Transmittance and NLTE Correction on Simulation of High Spectral Infrared Atmospheric Sounder onboard FY-3E

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Journal of meteorological Research 2024年第2期38卷 225-234页

作者： Chenggege FANG Peiming DONG Yang HAN Wanlin KAN Collaborative Innovation Center on Forecast and Evaluation of meteorological Disasters Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological AdministrationNanjing University of Information Science&TechnologyNanjing 210044 Donghai laboratory Zhoushan 316021 State key laboratory of Severe Weather Chinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing 100081 CMA Earth System Modeling and Prediction Centre China Meteorological Administration(CMA)Beijing 100081 key laboratory of Transportation Meteorology of China meteorological Administration Nanjing Joint Institute for Atmospheric SciencesNanjing 210041

With the launch of the first civilian early-morning orbit satellite Fengyun-3E(FY-3E),higher demands are placed on the accuracy of radiative transfer simulations for hyperspectral infrared ***,several key issues are investigated in the ***,the accuracy of the fast atmospheric transmittance model implemented in the Advanced Research and Modeling System(ARMS)has been evaluated with both the line-by-line radiative transfer model(LBLRTM)and the actual satellite *** results indicate that the biases are generally less than 0.25 K when compared to the LBLRTM,while below 1.0 K for the majority of the channels when compared to the ***,during both comparisons,significant biases are observed in certain *** accuracy of Hyperspectral Infrared Atmospheric Sounder-II(HIRAS-II)onboard FY-3E is comparable to,and even superior to that of the Cross-track Infrared Sounder(CrIS)onboard ***,apodization is a crucial step in the processing of hyperspectral data in that the apodization function is utilized as the instrument channel spectral response function to produce the satellite channel-averaged *** further explore the difference between the apodized and unapodized simulations,Sinc function is adopted in the fast transmittance *** is found that the use of Sinc function can make the simulations fit the original satellite observations *** simulating with apodized observations,the use of Sinc function exhibits larger deviations compared to the Hamming ***,a correction module is applied to minimize the impact of Non-Local Thermodynamic Equilibrium(NLTE)in the shortwave infrared *** is verified that the implementation of the NLTE correction model leads to a significant reduction in the bias between the simulation and observation for this band.

关键词： high spectral infrared sounding atmospheric transmittance apodization Non-Local Thermodynamic Equilibrium Fengyun-3E(FY-3E)

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Analysis of MIMO antenna array based on 3D Von Mises Fisher distribution

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The Journal of China Universities of Posts and Telecommunications 2015年第2期22卷 15-23页

作者： Zhou Jie Cao Zhigang Hisakazu Kikuchi jiangsu key laboratory of meteorological observation and Information processing Department of Electrical and Electronic Engineering

A three-dimensional （3D） Von Mises Fisher （VMF） distribution model was derived in multiple-input and multiple-output （MIMO） antenna communication environment. The azimuth of arrival and elevation of arrival are distributed for VMF distribution instead of the uniform or other traditional distributions. In particular the MIMO uniform Y-shaped array （UYA） and the uniform circular array （UCA） antenna topology are considered at mobile station and base station. The developed spatial fading correlation of the VMF model is determined by parameters of the concentration parameter, antenna spacing, mean azimuth of arrival, mean elevation of arrival. Using the channel model, the effects of the concentration parameter and the mean elevation angle on the capacity of MIMO antenna systems was analyzed. It is shown that the mean elevation of arrival must be taken into account in 3D MIMO communication environment.

关键词： MIMO antenna array VMF distribution spatial fading correlation channel capacity

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Combined UAMP and MF Message Passing Algorithm for Multi-Target Wideband DOA Estimation with Dirichlet Process Prior

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Tsinghua Science and Technology 2024年第4期29卷 1069-1081页

作者： Shanwen Guan Xinhua Lu Ji Li Rushi Lan Xiaonan Luo Guangxi key laboratory of Image and Graphic Intelligent processing Guilin University of Electronic TechnologyGuilin 541004China Guilin Huigu Institute of AI Industrial Technology Guilin 541004China School of Information Engineering Nanyang Institute of TechnologyNanyang 473000China

When estimating the direction of arrival (DOA) of wideband signals from multiple sources, the performance of sparse Bayesian methods is influenced by the frequency bands occupied by signals in different directions. This is particularly true when multiple signal frequency bands overlap. Message passing algorithms (MPA) with Dirichlet process (DP) prior can be employed in a sparse Bayesian learning (SBL) framework with high precision. However, existing methods suffer from either high complexity or low precision. To address this, we propose a low-complexity DOA estimation algorithm based on a factor graph. This approach introduces two strong constraints via a stretching transformation of the factor graph. The first constraint separates the observation from the DP prior, enabling the application of the unitary approximate message passing (UAMP) algorithm for simplified inference and mitigation of divergence issues. The second constraint compensates for the deviation in estimation angle caused by the grid mismatch problem. Compared to state-of-the-art algorithms, our proposed method offers higher estimation accuracy and lower complexity.

关键词： wideband direction of arrival(DOA)estimation sparse Bayesian learning(SBL) unitary approximate message passing(UAMP)algorithm Dirichlet process(DP)

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Mid-IR dual-wavelength difference frequency generation in uniform grating PPLN using index dispersion control

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Chinese Physics B 2013年第12期22卷 268-271页

作者：常建华孙青葛益娴王婷婷陶在红张闯 jiangsu key laboratory of meteorological observation and Information processing Nanjing University of Information Science & Technology Optics Division National Institute of Metrology

A novel widely tunable dual-wavelength mid-IR difference frequency generation （DFG） scheme with uniform grating periodically poled lithium niobate （PPLN） is presented in this paper. By using the temperature-dependent dispersion property of PPLN, the quasi-phase matching （QPM） peak for the pump may evolve into two separate ones and the wavelength spacing between them increases with the decrease of the crystal temperature. Such two pump QPM peaks may allow simultaneous dual-wavelength mid-IR laser radiations while properly setting the two fundamental pump wavelengths. With this scheme, mid-IR dual-wavelength laser radiations at around 3.228 and 3.548, 3.114 and 3.661, and 3.019 and 3.76 μm, are experimentally achieved for the crystal temperatures of 90, 65, and 30 ℃, respectively, based on the fiber laser fundamental lights.

关键词： mid-IR difference frequency generation quasi-phase matching dual-wavelength

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Non-crossing Quantile Regression Neural Network as a Calibration Tool for Ensemble Weather Forecasts

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Advances in Atmospheric Sciences 2024年第7期41卷 1417-1437页

作者： Mengmeng SONG Dazhi YANG Sebastian LERCH Xiang'ao XIA Gokhan Mert YAGLI Jamie M.BRIGHT Yanbo SHEN Bai LIU Xingli LIU Martin Janos MAYER School of Electrical Engineering and Automation Harbin Institute of TechnologyHarbin150001China Heidelberg Institute for Theoretical Studies Schloss-Wolfsbrunnenweg 3569118HeidelbergGermany Chair of Statistical Methods and Econometrics Karlsruhe Institute of Technology(KIT)Bluecherstr.1776185KarlsruheGermany key laboratory of Middle Atmosphere and Global Environment observation Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing100029China Solar Energy Research Institute of Singapore(SERIS) National University of Singapore(NUS)Singapore117574Singapore UK Power Networks LondonSE61NPUK China meteorological Administration Beijing100081China Heilongjiang meteorological Bureau Harbin150001China Department of Energy Engineering Faculty of Mechanical EngineeringBudapest University of Technology and EconomicsMűegyetem rkp.3H-1111BudapestHungary

Despite the maturity of ensemble numerical weather prediction(NWP),the resulting forecasts are still,more often than not,*** such,forecast calibration tools have become *** those tools,quantile regression(QR)is highly competitive in terms of both flexibility and predictive ***,a long-standing problem of QR is quantile crossing,which greatly limits the interpretability of QR-calibrated *** this point,this study proposes a non-crossing quantile regression neural network(NCQRNN),for calibrating ensemble NWP forecasts into a set of reliable quantile forecasts without *** overarching design principle of NCQRNN is to add on top of the conventional QRNN structure another hidden layer,which imposes a non-decreasing mapping between the combined output from nodes of the last hidden layer to the nodes of the output layer,through a triangular weight matrix with positive *** empirical part of the work considers a solar irradiance case study,in which four years of ensemble irradiance forecasts at seven locations,issued by the European Centre for Medium-Range Weather Forecasts,are calibrated via NCQRNN,as well as via an eclectic mix of benchmarking models,ranging from the naïve climatology to the state-of-the-art deep-learning and other non-crossing *** and stringent forecast verification suggests that the forecasts post-processed via NCQRNN attain the maximum sharpness subject to calibration,amongst all ***,the proposed conception to resolve quantile crossing is remarkably simple yet general,and thus has broad applicability as it can be integrated with many shallow-and deep-learning-based neural networks.

关键词： ensemble weather forecasting forecast calibration non-crossing quantile regression neural network CORP reliability diagram post-processing

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Generalized 3D Scattering Channel Model with MIMO Antenna Systems

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China Communications 2016年第5期13卷 66-81页

作者： Jie Zhou Hao Jiang Hisakazu Kikuchi Department of jiangsu key laboratory of meteorological observation and Information processing Nanjing University of Information Science and Technology Department of Electrical and Electronic Engineering Niigata University

In this paper, a generalized three-dimensional(3D) scattering channel model for macrocellular land mobile environments is considered. This model simultaneously describes angular arrival of multi-path signals in the azimuth and elevation planes in an environment where uniformly distributed scatterers are assumed to be present in hemispheroids around the base station(BS) and mobile station(MS). Using this channel model, we first derive the closed-form expression for the joint and marginal probability density functions of the angle-of-arrival and time-of-arrival measured at the BS and the MS corresponding to the azimuth and elevation angles. Next, we derive an expression for the Doppler spectral distribution caused by motion of the MSs. Furthermore, we analyze the performance of multiple-input multiple-output antenna systems numerically. The results show that the proposed 3D scattering channel model performs better than previously proposed two-dimensional(2D) models for indoor and outdoor environments. We compare the results with previous scattering channel models and measurement results to validate the generalizability of our model.

关键词： 3D scattering channel model angle of arrival Doppler spectra multiple-input multiple-output

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Compact and Tunable Mid-IR Light Source Based on a Dual-Wavelength Fiber Laser

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Chinese Physics Letters 2013年第11期30卷 106-108页

作者： CHANG Jian-Hua WANG Ting-Ting ZHANG Chuang GE Yi-Xian TAO Zai-Hong jiangsu key laboratory of meteorological observation and Information processing Nanjing University of Information Science&TechnologyNanjing 210044 jiangsu Technology&Engineering Center of meteorological Sensor Network Nanjing University of Information Science&TechnologyNanjing 210044

A compact,tunable mid-IR difference-frequency generation(DFG)light source based on a dual-wavelength fiber laser and a 5mol%MgO-doped periodically poled lithium niobate(MgO:PPLN)crystal is developed and *** output power of 233μW is achieved with a conversion efficiency of 0.1%/*** mid-IR wavelength can be tuned between 3308 nm and 3314 nm by changing the temperature of a pair of fiber Bragg grating(FBG)taking as cavity mirrors in the dual-wavelength fiber laser from 26.5°C to 106.5°C.

关键词： fiber tunable Dual

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Extraction of interface state density and resistivity of suspended p-type silicon nanobridges

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Journal of Semiconductors 2013年第5期34卷 7-12页

作者：张加宏刘清惓葛益娴顾芳李敏冒晓莉曹鸿霞 jiangsu key laboratory of meteorological observation and Information processing Nanjing University of Information Science & Technology College of Physics & Opto-Electronic Engineering Nanjing University of Information Science & Technology

The evaluation of the influence of the bending deformation of silicon nanobridges on their electrical properties is crucial for sensing and actuating applications. A combined theory/experimental approach for de- termining the resistivity and the density of interface states of the bending silicon nanobridges is presented. The suspended p-type silicon nanobridge test structures were fabricated from silicon-on-insulator wafers by using a standard CMOS lithography and anisotropic wet etching release process. After that, we measured the resistance of a set of silicon nanobridges versus their length and width under different bias voltages. In conjunction with a theoretical model, we have finally extracted both the interface state density of and resistivity suspended silicon nanobridges under different bending deformations, and found that the resistivity of silicon nanobridges without bending was 9.45 mΩ.cm and the corresponding interface charge density was around 1.7445 × 10^13 cm-2. The bending deformation due to the bias voltage slightly changed the resistivity of the silicon nanobridge, however, it significantly changed the distribution of interface state charges, which strongly depends on the intensity of the stress induced by bending deformation.

关键词： interface state density resistivity silicon nanobridges bias voltages

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Asymptotic solving method for sea-air coupled oscillator ENSO model

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Chinese Physics B 2012年第3期21卷 5-9页

作者：周先春姚静荪莫嘉琪 jiangsu key laboratory of meteorological observation and Information processing Nanjing University of Information Science and Technology College of Electronic and Information Engineering Nanjing University of Information Science & Technology Anhui Normal University

The ENSO is an interannual phenomenon involved in the tropical Pacific ocean-atmosphere *** this article,we create an asymptotic solving method for the nonlinear system of the ENSO *** asymptotic solution is *** then we can furnish weather forecasts theoretically and other behaviors and rules for the atmosphere-ocean oscillator of the ENSO.

关键词： nonlinear system asymptotic solution sea-air coupled oscillator

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STUDY OF THE RELATIONSHIP BETWEEN IWC AND Z FOR NONSPHERICAL ICE PARTICLES AT MILLIMETER WAVELENGTH

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Journal of Tropical Meteorology 2016年第S1期22卷 78-88页

作者：王金虎葛俊祥魏鸣顾松山杨泽鑫 jiangsu key laboratory of meteorological observation and Information processing Nanjing University of Information Science and Technology key laboratory for Aerosol-Cloud-Precipitation of China meteorological Administration Nanjing University of Information Science and Technology

Ice water content(IWC) plays important roles in weather and climate *** the IWCs of cirrus clouds with millimeter-wavelength radar can be problematic due to influences of ice particle rotation on their backscattering cross *** here introduce models to describe the radiation patterns of six nonspherical particles of specific *** using HFSS software were applied to describe the differences resulting from different orientations and equivalent spheres.A double exponential function was used for fitting to describe the relationship between the particles' maximum sizes and backscattering cross *** backscattering cross sections of nonspherical ice particles were computed by the method of moment,and those of the equivalent spherical particles were computed by Lorenz-Mie theory for three different orientations:fixed,horizontal,and *** that a mixture of nonspherical ice particles follows the B-H mixing model,the size distribution of cirrus particles obeys the exponential distribution measured by NASA in *** computing the IWCs of cirrus clouds,which follows the above mentioned B-H model and exponential distribution,the radar reflectivity factors of nonspherical ice particles and equivalent spheres at three different orientations can be ***,the IWC results can be acquired by inputting the radar reflectivity variables into the well-known IWC-Z *** analysis described here demonstrates that when using the radar reflectivity Z,the orientation must be considered in order to determine the *** equivalent sphere theory,the derived IWCs underestimate the actual *** results are important for accurately retrieving the microphysical parameters of cirrus clouds.

关键词： method of moment ice particles radar reflectivity factor ice water content

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