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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 data.Therefore,several key issues are investigated in the paper.First,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 observations.The 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 observations.However,during both comparisons,significant biases are observed in certain channels.The 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 NOAA-20.Furthermore,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 transmittance.To further explore the difference between the apodized and unapodized simulations,Sinc function is adopted in the fast transmittance model.It is found that the use of Sinc function can make the simulations fit the original satellite observations better.When simulating with apodized observations,the use of Sinc function exhibits larger deviations compared to the Hamming function.Moreover,a correction module is applied to minimize the impact of Non-Local Thermodynamic Equilibrium(NLTE)in the shortwave infrared band.It 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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Novel Apodized Fiber Bragg GratingApplied for Medical Sensors:Performance Investigation

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Computer Modeling in Engineering & Sciences 2023年第4期135卷 301-323页

作者： Ramya Arumugam Ramamoorthy Kumar Samiappan Dhanalakshmi Khin Wee Lai Lei Jiao Xiang Wu Department of Electronics and Communication Engineering College of Engineering and TechnologySRM Institute of Science and TechnologyKattankulathurChengalpattu603203India Department of Biomedical Engineering Faculty of EngineeringUniversiti MalayaKuala Lumpur50603Malaysia General Hospital of Xuzhou Mining Group Xuzhou221000China School of Medical Information&Engineering Xuzhou Medical UniversityXuzhou221000China

Sensors play an important role in shaping and monitoring human health.Exploration of methods to use Fiber Bragg Grating(FBG)with enhanced sensitivity has attracted great interest in the field of medical research.In this paper,a novel apodization function is proposed and performance evaluation and optimization of the same have been made.A comparison was conducted between various existing apodization functions and the proposed one based on optical characteristics and sensor parameters.The results evince the implementation of the proposed apodization function for vital sign measurement.The optical characteristics considered for evaluation are Peak Resonance Reflectivity level,Side Lobes Reflectivity level and FullWidth HalfMaximum(FWHM).The proposed novel apodization novel function has better FWHM,which is narrower than the FWHM of uniform FBG.Sensor characteristics like a quality parameter,detection accuracy and sensitivity also show improvement.The proposed novel apodization function is demonstrated to have a better shift in wavelength in terms of temperature and pulse measurement than the existing functions.The sensitivity of the proposed apodized function is enhanced with a Poly-dimethylsiloxane coating of varying thickness,which is 6 times and 5.14 times greater than uniform Fiber Bragg grating and FBG with the proposed novel apodization function,respectively,enhancing its utilization in the field of medicine.

关键词： Fiber bragg grating apodization optical sensing temperature strain sensitivity

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Design and simulation of a 2-D array flexible ultrasound transducer system for tissue characterization-A pilot study

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Medicine in Novel Technology and Devices 2022年第1期13卷 59-64页

作者： Zhihua Gan Brian Guo Jiqi Cheng Yi-Xian Qin Department of Biomedical Engineering Stony Brook UniversityStony BrookNY11794USA Department of Electrical and Computer Engineering Stony Brook UniversityStony BrookNY11794USA

Noninvasive diagnosis of bone density and mechanical properties using non-radiation imaging modality is an emerging area with promising in early prediction of osteopenia and treatment effectiveness in the clinic and functional disuse,i.e.,long-term bedrest and space mission.Advances in quantitative ultrasound have shown advantages in measuring both bone density and mechanical strength,non-radiation,imaging capability,and easy to use.The challenge that remained is the poor penetration of ultrasound signals passing through trabecular and cortical bones and acoustic energy scattering.A new scanning confocal ultrasound technology is developed in this lab to detect the alteration of bone to provide diagnostic results in bone density and structure properties.A software-controlled flexible ultrasound system with 2-D dual array transducer is developed and proposed for the purpose of noninvasive bone density diagnosis and assessment of bone loss.Transmitting(Tx)transducer elements are divided into sub-blocks to excite the ultrasound signals in sequence to decrease the system complexity while maintaining beam pattern properties by the signal processing procedure at receiving(Rx)side.apodization is also applied to reduce acoustic side lobes and to make the resolution in the ultrasound field of view(FOV)more uniform.This study may provide basic understanding of modulated confocal ultrasound beam forming for tissue characterization,such as trabecular bone structual and strength properties.

关键词： Flexible ultrasound system Noninvasive diagnostic imaging Sub-block triggering Ultrasound imaging resolution apodization Quantitative ultrasound Trabecular bone property Scanning ultrasound Bone density and strength

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Development of high damage threshold laser-machined apodizers and gain filters for laser applications

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High Power Laser Science and Engineering 2016年第3期4卷 113-119页

作者： Patrick Rambo Jens Schwarz Mark Kimmel John L.Porter Sandia National Laboratories

We have developed high damage threshold filters to modify the spatial profile of a high energy laser beam. The filters are formed by laser ablation of a transmissive window. The ablation sites constitute scattering centers which can be filtered in a subsequent spatial filter. By creating the filters in dielectric materials, we see an increased laser-induced damage threshold from previous filters created using ‘metal on glass' lithography.

关键词： apodization laser beam shaping laser micro-machining spatial filtering

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