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A Deep-Learning and Transfer-Learning Hybrid Aerosol retrieval algorithm for FY4-AGRI:Development and Verification over Asia

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Engineering 2024年第7期38卷 164-174页

作者： Disong Fu Hongrong Shi Christian AGueymard Dazhi Yang Yu Zheng Huizheng Che Xuehua Fan Xinlei Han Lin Gao Jianchun Bian Minzheng Duan Xiangao Xia Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 10029China Key Laboratory of Cloud-Precipitation Physics and Severe Storms Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Solar Consulting Services ColebrookNH 03576USA School of Electrical Engineering and Automation Harbin Institute of TechnologyHarbin 150006China State Key Laboratory of Severe Weather&Key Laboratory of Atmospheric Chemistry Institute of Atmospheric Composition and Environmental MeteorologyChinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing 100081China National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing100085China Key Laboratory of Compound and Chained Natural Hazards Dynamics Ministry of Emergency Management of ChinaBeijing 100085China h National Satellite Meteorological Center China Meteorological AdministrationBeijing 100081China University of Chinese Academy of Sciences Beijing 100049China

The Advanced Geosynchronous Radiation Imager(AGRI)is a mission-critical instrument for the Fengyun series of *** acquires full-disk images every 15 min and views East Asia every 5 min through 14 spectral bands,enabling the detection of highly variable aerosol optical depth(AOD).Quantitative retrieval of AOD has hitherto been challenging,especially over *** this study,an AOD retrieval algorithm is proposed that combines deep learning and transfer *** algorithm uses core concepts from both the Dark Target(DT)and Deep Blue(DB)algorithms to select features for the machinelearning(ML)algorithm,allowing for AOD retrieval at 550 nm over both dark and bright *** algorithm consists of two steps:①A baseline deep neural network(DNN)with skip connections is developed using 10 min Advanced Himawari Imager(AHI)AODs as the target variable,and②sunphotometer AODs from 89 ground-based stations are used to fine-tune the DNN ***-of-station validation shows that the retrieved AOD attains high accuracy,characterized by a coefficient of determination(R2)of 0.70,a mean bias error(MBE)of 0.03,and a percentage of data within the expected error(EE)of 70.7%.A sensitivity study reveals that the top-of-atmosphere reflectance at 650 and 470 nm,as well as the surface reflectance at 650 nm,are the two largest sources of uncertainty impacting the *** a case study of monitoring an extreme aerosol event,the AGRI AOD is found to be able to capture the detailed temporal evolution of the *** work demonstrates the superiority of the transfer-learning technique in satellite AOD retrievals and the applicability of the retrieved AGRI AOD in monitoring extreme pollution events.

关键词： Aerosol optical depth retrieval algorithm Deep learning Transfer learning Advanced Geosynchronous Radiation Imager

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retrieval algorithm of sea surface wind vectors for WindSat based on a simple forward model

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Chinese Journal of Oceanology and Limnology 2013年第1期31卷 210-218页

作者：赵屹立 College of Information Science and Engineering Ocean University of China Department of Remote Sensing and Mapping National Ocean Technology Center

WindSat/Coriolis is the first satellite-borne polarimetric microwave radiometer, which aims to improve the potential of polarimetric microwave radiometry for measuring sea surface wind vectors from space. In this paper, a wind vector retrieval algorithm based on a novel and simple forward model was developed for WindSat. The retrieval algorithm of sea surface wind speed was developed using multiple linear regression based on the simulation dataset of the novel forward model. Sea surface wind directions that minimize the difference between simulated and measured values of the third and fourth Stokes parameters were found using maximum likelihood estimation, by which a group of ambiguous wind directions was obtained. A median filter was then used to remove ambiguity of wind direction. Evaluated with sea surface wind speed and direction data from the U.S. National Data Buoy Center （NDBC）, root mean square errors are 1.2 rn/s and 30~ for retrieved wind speed and wind direction, respectively. The evaluation results suggest that the simple forward model and the retrieval algorithm are practicable for near-real time applications, without reducing accuracy.

关键词： polarimetric microwave radiometer sea surface wind vector retrieval algorithm WindSat

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A retrieval algorithm of Sheet Metal Parts Based on Relationships of Features

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Chinese Journal of Aeronautics 2012年第3期25卷 453-472页

作者： WANG Dawei YAN Guangrong LEI Yi ZHANG Jiaying School of Mechanical Engineering and Automation Beihang University Beijing 100191. China Modern Education Center. Shandong University of Science and Technology. Ta ian 271019. China

With the rapid increase in the number of three-dimensional （3D） models each year, to quickly and easily find the part desired has become a big challenge of enterprises. Meanwhile, many methods and algorithms have been proposed for part retrieval. However, most of the existing methods are designed lbr mechanical parts, and can not be well worked for sheet metal part re- trieval. An approach to feature-based retrieval of sheet metal parts is presented. Firstly, the features frequently used in sheet metal part design are chosen as the ＂＇key words＂ in retrieval. Based on those features, a relative position model is built to express the different relationships of the features in 3D space. Secondly, a description method of the model is studied. With the descrip- tion method the relative position of features in sheet metal parts can be expressed by four location description matrices. Thirdly, based on the relative position model and location description matrices, the equivalent definition of relationships of two feature groups is given which is the basis to calculate the similarity of two sheet metal parts. Next, the tbrmula of retrieval algorithm for sheet metal parts is given. Finally, a prototype system is developed to test and verify the effectiveness of the retrieval method suggested. Experiments verify that the new method is able to meet the requirements of searching sheet metal parts and possesses potentials in practical application.

关键词： CAD sheet metal retrieval algorithm features search 3D model

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Research on the Multimedia Information retrieval algorithm based on Information Restructuring and Image Reconstruction

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International Journal of Technology Management 2016年第3期 36-39页

作者： Nian Li Wuhan Donghu University No.301WenhuaroadJiangxia WuhanHubei China430212

In this paper, we conduct research on the multimedia information retrieval algorithm based on the information restructuring and image reconstruction. With the massive growth of information resources, people through various retrieval tools for too much information, led directly to information overload. In vector space model and probability retrieval model based on information retrieval tools rarely consider the user＇ s personalized information needs and features, has resulted in a large amount of information retrieval result and correlation information the user＇ s information demand is not big. In order to improve the existing retrieval system, in recent years, scholars to study looked that context information retrieval context factors need to be considered, such as the retrieval time, place and the interactive history, mission, environment and other factors stated or implied in the retrieval process. At present, the context research has become the information behavior, information search process and the research hotspot in the field of information retrieval interaction.

关键词： Multimedia Information retrieval algorithm Image Reconstruction Data Analysis.

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An algorithm for retrieval of aerosol optical properties over the turbid waters from GOCI

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Marine Science Bulletin 2017年第1期19卷 67-75页

作者： ZHANG Ya-nan ZHENG Xiao-shen College of Marine and Environmental Science Tianjin University of Science and Technology Tianjin300457 China

Aimed at high turbid coastal waters, an improved algorithm for retrieval ofaerosol optical properties from Geostationary Ocean Color Imager （GOCI） is *** algorithm adopts support vector machine （SVM） to separate the interfering signalof phytoplankton pigments, suspended matter and chromophoric dissolved organicmatter （CDOM）. Radioactive Transfer Model （RTM） Rstar5b is utilized to simulate thetransmitting process. The algorithm can retrieve aerosol optical depth （AOD） andaerosol types simultaneously. In the study, the aerosol optical depth was retrieved overthe turbid waters in the summer of 2014 and 2015. The results of inversion werecompared with the corresponding AERONET data and GOCI service product toestimate the accuracy of the advanced method. The study shows that this algorithmhas better performance compared with GOCI service algorithm for turbid water in theYellow Sea.

关键词： aerosol optical depth turbid waters retrieval algorithm

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An assessment of arctic sea ice concentration retrieval based on “HY-2” scanning radiometer data using field observations during CHINARE-2012 and other satellite instruments

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Acta Oceanologica Sinica 2015年第3期34卷 42-50页

作者： SHI Lijiang LU Peng CHENG Bin KARVONEN Juha WANG Qimao LI Zhijun HAN Hongwei National Satellite Ocean Application Service State Oceanic Administration Laboratory of Coastal and Offshore Engineering Dalian University of Technology Finnish Meteorological Institute

A retrieval algorithm of arctic sea ice concentration （SIC） based on the brightness temperature data of “HY-2” scanning microwave radiometer has been constructed. The tie points of the brightness temperature were selected based on the statistical analysis of a polarization gradient ratio and a spectral gradient ratio over open water （OW）, first-year ice （FYI）, and multiyear ice （MYI） in arctic. The thresholds from two weather filters were used to reduce atmospheric effects over the open ocean. SIC retrievals from the “HY-2” radiom-eter data for idealized OW, FYI, and MYI agreed well with theoretical values. The 2012 annual SIC was calcu-lated and compared with two reference operational products from the National Snow and Ice Data Center （NSIDC） and the University of Bremen. The total ice-covered area yielded by the “HY-2” SIC was consistent with the results from the reference products. The assessment of SIC with the aerial photography from the fifth Chinese national arctic research expedition （CHINARE） and six synthetic aperture radar （SAR） images from the National Ice Service was carried out. The “HY-2” SIC product was 16% higher than the values de-rived from the aerial photography in the central arctic. The root-mean-square （RMS） values of SIC between “HY-2” and SAR were comparable with those between the reference products and SAR, varying from 8.57% to 12.34%. The “HY-2” SIC is a promising product that can be used for operational services.

关键词： “HY-2” scanning microwave radiometer retrieval algorithm sea ice concentration arctic

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The TanSat mission： preliminary global observations

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Science Bulletin 2018年第18期63卷 1200-1207页

作者： Yi Liu Jing Wang Lu Yao Xi Chen Zhaonan Cai Dongxu Yang Zengshan Yin Songyan Gu Longfei Tian Naimeng Lu Daren Lyu Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029 China University of Chinese Academy of Sciences Beijing 100049 China Shanghai Engineering Center for Microsatellites Shanghai 201210 China National Satellite Meteorological Center China Meteorological Administration Beijing 100081 China

The Chinese global carbon dioxide monitoring satellite （TanSat） was launched successfully in December 2016 and has completed its on-orbit tests and calibration. TanSat aims to measure the atmospheric column-averaged dry air mole fractions of carbon dioxide （XCO2） with a precision of 4 ppm at the regional scale, and in addition, to derive global and regional CO2 fluxes. Progress towards these objectives is reviewed and the first scientific results from TanSat measurements are presented. TanSat on-orbit tests indicate that the Atmospheric Carbon dioxide GratingSpectrometer is in normal working status and is beginning to produce LIB products. The preliminary TanSat XCO2 products have been retrieved by an algorithm and compared to NASA Orbiting Carbon Observatory-2 （OCO-2） measurements during an over- lapping observation period. Furthermore, the XCO2 retrievals have been validated against eight groundsite measurement datasets from the Total Carbon Column Observing Network, for which the preliminary conclusion is that TanSat has met the precision design requirement, with an average bias of 2.11 ppm. The first scientific observations are presented, namely, the seasonal distributions of XCO2 over land on a global scale.

关键词： TanSat Carbon dioxide retrieval algorithm Carbon flux inversion

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An algorithm to Retrieve Precipitation with Synthetic Aperture Radar

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Journal of Meteorological Research 2016年第3期30卷 401-411页

作者：谢亚楠刘志坤安大伟 Key Laboratory of Specialty Fiber Optics and Optical Access Networks Shanghai UniversityShanghai 200072 National Satellite Meteorological Center Beijing 100081

This paper presents a new type of rainfall retrieval algorithm,called the model-oriented statistical and Volterra *** is a combination of the model-oriented statistical（MOS） and Volterra integral equation（VIE） *** steps involved in this new algorithm can be briefly illustrated as ***,information such as the start point and width of the rain is obtained through pre-analysis of the data received by synthetic aperture radar（SAR）.Secondly,the VIE retrieval algorithm is employed over a short distance to obtain information on the shape of the ***,the rain rate can be calculated by using the MOS retrieval *** results show that the proposed algorithm is effective and simple,and can lead to time savings of nearly 50%compared with *** example of application of SAR data is also discussed,involving the retrieval of precipitation information over the South China Sea.

关键词： microwave remote sensing precipitation retrieval algorithm synthetic aperture radar

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Assessment of total suspended sediment concentrations in Poyang Lake using HJ-1A/1B CCD imagery

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Chinese Journal of Oceanology and Limnology 2012年第2期30卷 295-304页

作者：于之锋陈晓玲周斌田礼乔袁小红冯炼 State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing(LIESMARS)Wuhan University Institute of Remote Sensing and Earth Sciences Hangzhou Normal University Zhejiang Provincial Key Laboratory of Urban Wetlands and Regional Change Key Laboratory of Poyang Lake Wetland and Watershed Research Ministry of EducationJiangxi Normal University

We explored the potential of the environment and disaster monitoring and forecasting small satellite constellations (HJ-1A/1B satellites) charge-coupled device (CCD) imagery (spatial resolution of 30 m, revisit time of 2 days) in the monitoring of total suspended sediment (TSS) concentrations in dynamic water bodies using Poyang Lake, the largest freshwater lake in China, as an example. Field surveys conducted during October 17-26, 2009 showed a wide range of TSS concentration (3-524 mg/L). Atmospheric correction was implemented using the Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes (FLAASH) module in ENVI with the aid of aerosol information retrieved from concurrent Terra/Moderate Resolution Imaging Spectroradiometer (MODIS) surveys, which worked well at the CCD bands with relatively high reflectance. A practical exponential retrieval algorithm was created between satellite remote sensing reflectance and in-situ measured TSS concentration. The retrieved results for the whole water area matched the in-situ data well at most stations. The retrieval errors may be related to the problem of scale matching and mixed pixel. In three selected subregions of Poyang Lake, the distribution trend of retrieved TSS was consistent with that of the field investigation. It was shown that HJ-1A/1B CCD imagery can be used to estimate TSS concentrations in Poyang Lake over synoptic scales after applying an appropriate atmospheric correction method and retrieval algorithm.

关键词： total suspended sediment HJ-1A/1B CCD atmospheric correction retrieval algorithm Poyang Lake

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A new algorithm of retrieving a petroleum substances absorption coefficient in sea water based on a remote sensing image

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Acta Oceanologica Sinica 2016年第11期35卷 97-104页

作者： HUANG Miaofen XING Xufeng SONG Qingjun LIU Yang DONG Wentong School of mathematics and computer Guangdong Ocean University Zhanjiang 524088 China National Satellite Ocean Application Service State Oceanic Administration Beijing 100081 China Petro China Exploration and Development Research Institute Beijing 100083 China

Establishing the remote sensing algorithm of retrieving the absorption coefficient of seawater petroleum substances is an efficient way to improve the accuracy of retrieving a seawater petroleum concentration using a remote sensing technology. A remote sensing reflectance is a basic physical parameter in water color remote sensing. Apply it to directly retrieve the absorption coefficient of seawater petroleum substances is of potential advantage. The absorption coefficient of waters containing petroleum [ACWCP, a_o（λ）], consists of the absorption coefficient of pure water [ACPW, a_w（λ）], plankton [ACP, a_（ph）（λ）], colored scraps [ACCS, a_（d,g）（λ）], and petroleum substance [ACPS, a_（oil）（λ）]. Among those, ACCS consists of the absorption coefficient of nonalgal particle [ACNP, a_d（λ）] and colored dissolved organic matter [ACCDOM, a_g（λ）]. For waters containing petroleum, the retrieved ACCS using the existing method is a combination absorption coefficient of ACNP,ACCDOM and ACPA [CAC, a_（d,g,oil）（λ）]. Therefore, the principle question is how to extract ACPS from *** the analysis of the three proportion tests conducted between the year of 2013 and 2015 and the corresponding remote sensing data, an algorithm of retrieving the absorption coefficient of petroleum substances is proposed based on remote sensing reflectance. First of all, ACPS and CAC are retrieved from the reflectance using the quasi-analytical algorithm（QAA）, with some parameter modified. Secondly, given the fact that the backscatter coefficient [BC, b_（bp）（555）] of total particles at 555 nm can be obtained completely from the reflectance, the relation between BC and ACNP in petroleum contaminated water can be established. As a result, ACNP can be calculated. Then, combining the remote sensing retrieving algorithm of a_g（440）, the method of achieving the spectral slope of the absorption coefficient can be established, from which ACCDOM,can be calculated. Finally, ACPS can be computed as the residual

关键词： petroleum substances in sea water remote sensing technology absorption coefficient retrieval algorithm

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