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Chinese Optics Letters 2024年第4期22卷 119-124页

作者：贾俊连董博宇陶理施剑阳迟楠张俊文 Key Laboratory of EMW Information(MoE) Fudan UniversityShanghai 200433China Shanghai ERC of LEO satellite Communication and applications Shanghai CIC of LEO Satellite Communication TechnologyShanghai 200433China Science and Technology on Electromagnetic Compatibility Laboratory China Ship Development and Design CentreWuhan 430000China Peng Cheng Laboratory Shenzhen 518055China

This paper experimentally demonstrates a distributed photonics-based W-band integrated sensing and communication(ISAC) system, in which radar sensing can aid the communication links in alignment and data rate estimation. As a proof-of-concept, the ISAC system locates the users, guides the alignment, and sets a communication link with the estimated highest data rate. A peak net data rate of 68.6 Gbit/s and a target sensing with a less-than-1-cm error and a sub-2-cm resolution have been tested over a 10-km fiber and a 1.15-m free space transmission in the photonics-based W-band ISAC system. The achievable net data rates of the users at different locations estimated by sensing are experimentally verified.

关键词： integrated sensing and communication photonics-aided technique W-band radar-aided flexible communication

Progress and Achievements of Fengyun Meteorological satellite Program since 2022

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空间科学学报 2024年第4期44卷 712-721页

作者： GUAN Min WANG Jingsong ZHAO Xiangang QIN Danyu FAN Cunqun XIAN Di LIU Chang National satellite Meteorological Center(National Centre for Space Weather) Beijing 100081 Innovation Center for Fengyun Meteorological satellite(FYSIC) Beijing 100081 Key Laboratory of Radiometric Calibration and Validation for Environmental satellites/Key Laboratory of Space Weather China Meteorological AdministrationBeijing 100081

Fengyun meteorological satellites have undergone a series of significant developments over the past 50 *** generations,four types,and 21 Fengyun satellites have been developed and launched,with 9 currently operational in *** data obtained from Fengyun satellites is employed in a multitude of applications,including weather forecasting,meteorological disaster prevention and reduction,climate change,global environmental monitoring,and space *** data products and services are made available to the global community,resulting in tangible social and economic *** 2023,two Fengyun meteorological satellites were successfully *** report presents an overview of the two recently launched Fengyun satellites and currently in orbit Fengyun satellites,including an evaluation of their remote sensing instruments since ***,it addresses the subject of Fengyun satellite data archiving,data services,application services,international cooperation,and supporting ***,the development prospects have been outlined.

关键词： Fengyun meteorological satellites Data services and application International cooperation and support

Low-cost,large-coverage,and high-flexibility coherent PON for next-generation access networks:advances,challenges,and prospects[Invited]

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Chinese Optics Letters 2024年第4期22卷 26-35页

作者：邢思哲张俊文申王伟颜安李国强孙奥龙周骥郭栋施剑阳李子薇沈超迟楠 Key Laboratory of EMW Information(MoE) Fudan UniversityShanghai 200433China Department of Communication Science and Engineering Shanghai ERC of LEO Satellite Communication and ApplicationsShanghai CIC of LEO Satellite Communication TechnologyFudan UniversityShanghai 200433China Department of Electronic Engineering Jinan UniversityGuangzhou 510632China School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China

Increasing bandwidth requirements have posed significant challenges for traditional access *** is difficult for intensity modulation/direct detection to meet the power budget and flexibility requirements of the next-generation passive optical network(PON)at 100G and beyond considering the new *** is driving researchers to develop novel optical access ***-cost,wide-coverage,and high-flexibility coherent PON is emerging as a strong contender in the *** this article,we will review technologies that reduce the complexity of coherent PON(CPON),enabling it to meet the commercial ***,advanced algorithms and architectures that can enhance system coverage and flexibility are also discussed.

关键词： access network coherent optics flexible data rate low complexity wide dynamic range

Operational Characteristics of Loop Heat Pipe in Microgravity and Normal Gravity Environments

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Journal of Thermal Science 2024年第4期33卷 1394-1408页

作者： ZHONG Siyuan XIE Rongjian LI Yunfei SUN Xiaojin Shanghai Institution of Technology and Physics Shanghai200083China University of Chinese Academy of Sciences Beijing100049China Shanghai Institute of satellite Engineering Shanghai200240China

The loop heat pipe(LHP)is an advanced,efficient two-phase heat transfer unit,whose operational performance may be affected by microgravity conditions in contrast to ground-based *** performance of on-orbit temperature data and ground test of a copper-propylene LHP with a condenser temperature range of 243.15 K to 303.15 K were employed to compared and *** LHP has successfully started up for more than 193 times with a good heat transfer performance and a stable start-up stabilization on-orbit under a complex orbital heating environment for more than eight *** a small heat load(10.0W),the average start-up time is 110.0 s while the start-up temperature ranges from 5.71 K-12.78 *** start-up time at large temperature differences in the high temperature zone will be higher than the time required for start-up at smaller temperature differences in the low *** the condenser temperature is 250.0 K,the stable temperature difference on orbit is 3.83 K,which is generally consistent in heat transfer compared to 2.20 K in the ground *** this paper,we can conclude that the on-orbit flight data up to now can provide a reference to the design of subsequent LHP space applications.

关键词： Loop Heat Pipe(LHP) start up microgravity on-orbit experiment

Networking Observation and applications of Chinese Ocean satellites

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空间科学学报 2024年第4期44卷 722-730页

作者： ZOU Bin LIU Yuxin National satellite Ocean Application Service Beijing 100081 Key Laboratory of Space Ocean Remote Sensing and Application Ministry of Natural ResourcesBeijing 100081

This paper presents the networking observation capabilities of Chinese ocean satellites and their diverse applications in ocean disaster prevention,ecological monitoring,and resource *** the inaugural launch in 2002,China has achieved substantial advancements in ocean satellite technology,forming an observation system composed of the HY-1,HY-2,and HY-3 series *** satellites are integral to global ocean environmental monitoring due to their high resolution,extensive coverage,and frequent *** forward,China aims to further enhance and expand its ocean satellite capabilities through ongoing projects to support global environmental protection and sustainable development.

关键词： Chinese ocean satellites Networking observation Ocean forecasting Ocean disaster prevention and mitigation Ocean ecological monitoring Ocean resource development Polar monitoring Terrestrial applications

Monitoring Multi-Temporal Changes of Lakes on the Tibetan Plateau Using Multi-Source Remote Sensing Data from 1992 to 2019: A Case Study of Lake Zhari Namco

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Journal of Earth Science 2024年第5期35卷 1679-1691页

作者： Juan Wu Chang-Qing Ke Yu Cai Zheng Duan Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology Key Laboratory for Land Satellite Remote Sensing Applications of Ministry of Natural ResourcesSchool of Geography and Ocean ScienceNanjing University Collaborative Innovation Center of Novel Software Technology and Industrialization Guangxi Water and Power Design Institute Co. Ltd Collaborative Innovation Center of South China Sea Studies Department of Physical Geography and Ecosystem Science Lund University

Lake level, area and volume are sensitive indicators of climate change. At present, many studies have focused on the interannual water balance of lakes, but lake level and area can change remarkably with seasons, especially for lakes with seasonal ice cover. Zhari Namco, a seasonal frozen lake, was selected as an example to investigate its seasonal water balance. Multi-source altimetry and Landsat data were used to obtain the seasonal lake level and area from 1992 to 2019, and seasonal lake volume variations were also estimated. The results indicated the average lake level, area and volume in autumn were the largest. The lake level, area, and volume experienced three turning points approximately in 2000, 2010, and 2016, and showed an overall increasing trend from 1992 to 2019, with slopes of 0.15 m/year, 2.17 km2/year, and 0.14 km3/year, respectively. The lake area expanded significantly in autumn, which was related to the abundant precipitation. Delay time of land surface runoff, increased temperature, and evaporation may be the reason for the low lake level and volume in summer. The precipitation was the dominant factor of water balance, which explained 62.09%, 62.43%, and 62.10% of the variations in lake level, area, and volume, respectively.

关键词： lake level lake area lake volume satellite altimetry landsat Zhari Namco hydrogeology

Quantitative applications of Weather satellite Data for Nowcasting:Progress and Challenges

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Journal of Meteorological Research 2024年第3期38卷 399-413页

作者： Jun LI Jing ZHENG Bo LI Min MIN Yanan LIU Chian-Yi LIU Zhenglong LI WPaul MENZEL Timothy J.SCHMIT John L.CINTINEO Scott LINDSTROM Scott BACHMEIER Yunheng XUE Yayu MA Di DI Han LIN Innovation Centre for Fengyun Meteorological satellite(FYSIC) National Satellite Meteorological CentreChina Meteorological AdministrationBeijing100081China School of Atmospheric Sciences and Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies Sun Yat-sen University and Southern Laboratory of Ocean Science and EngineeringZhuhai519082China Key Laboratory of Geographic Information Science(Ministry of Education) East China Normal UniversityShanghai200241China Research Center for Environmental Changes Academia SinicaTaipei11529China Cooperative Institute for Meteorological satellite Studies University of Wisconsin-MadisonMadisonWI53706USA Sensors and Calibration Branch STAR/NESDISMadisonWI53706USA Wuxi University Wuxi214105China School of Computer Science Chengdu University of Information TechnologyChengdu610225China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing210044China Key Laboratory of Spatial Data Mining and Information Sharing of Ministry of Education National and Local Joint Engineering Research Center of Satellite Geospatial Information TechnologyFuzhou UniversityFuzhou350108China

Monitoring and predicting highly localized weather events over a very short-term period,typically ranging from minutes to a few hours,are very important for decision makers and public *** these events usually relies on radar observations through monitoring and *** advanced high-resolution imaging and sounding observations from weather satellites,nowcasting can be enhanced by combining radar,satellite,and other data,while quantitative applications of those data for nowcasting are advanced through using machine learning *** applications include monitoring the location,impact area,intensity,water vapor,atmospheric instability,precipitation,physical properties,and optical properties of the severe storm at different stages(pre-convection,initiation,development,and decaying),identification of storm types(wind,snow,hail,etc.),and predicting the occurrence and evolution of the *** observations can provide information on the environmental characteristics in the preconvection stage and are very useful for situational awareness and storm *** paper provides an overview of recent progress on quantitative applications of satellite data in nowcasting and its challenges,and future perspectives are also addressed and discussed.

关键词： weather satellite quantitative applications nowcasting pre-convection

A real-time performance improvement method for composite time scale

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Chinese Physics B 2024年第9期33卷 350-357页

作者： Fangmin Wang Wenlin Li Hongfei Dai Chunyi Li Jianhua Zhou Shenhui Xue Bo Wang State Key Laboratory of Precision Space–time Information Sensing Technology Department of Precision InstrumentTsinghua UniversityBeijing 100084China Key Laboratory of Photonic Control Technology(Tsinghua University) Ministry of EducationBeijing 100084China Beijing satellite Navigation Center Beijing 100094China

The composite time scale(CTS)provides a stable,accurate,and reliable time scale for modern *** improvement of CTS’s real-time performance will improve its stability,which strengths related applications’*** at this goal,a method achieved by determining the optimal calculation interval and accelerating adjustment stage is proposed in this *** determinants of the CTS’s calculation interval(characteristics of the clock ensemble,the measurement noise,the time and frequency synchronization system’s noise and the auxiliary output generator noise floor)are studied and the optimal calculation interval is *** also investigate the effect of ensemble algorithm’s initial parameters on the CTS’s adjustment stage.A strategy to get the reasonable initial parameters of ensemble algorithm is *** results show that the adjustment stage can be finished rapidly or even can be shorten to zero with reasonable initial *** this basis,we experimentally generate a distributed CTS with a calculation interval of 500 s and its stability outperforms those of the member clocks when the averaging time is longer than1700 *** experimental result proves that the CTS’s real-time performance is significantly improved.

关键词： composite time scale real-time performance calculation interval adjustment stage

Methods for ice velocity mapping in West Antarctica using historical optical satellite images

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Advances in Polar Science 2024年第2期35卷 252-263页

作者： ZHANG Yujie AN Lu TANG Leyue LI Hongwei HE Meixi LI Rongxing Center for Spatial Information Science and Sustainable Development applications Tongji UniversityShanghai 200092China College of Surveying and Geo-Informatics Tongji UniversityShanghai 200092China

The Antarctic Ice Sheet harbors more than 90%of the Earth ice mass,with significant losses experienced through dynamic thinning,particularly in West *** crucial aspect of investigating ice mass balance in historical periods preceding 1990 hinges on the utilization of ice velocities derived from optical satellite *** employed declassified satellite images and Landsat images with normalized cross correlation based image matching,adopting an adaptive combination of skills and methods to overcome challenges encountered during the mapping of historical ice velocity in West Antarctica.A basin-wide synthesis velocity map encompassing the coastal regions of most large-scale glaciers and ice shelves in West Antarctica has already been successfully *** results for historical ice velocities cover over 70%of the grounding line in most of the West Antarctic *** adjustments,we uncovered overestimations in ice velocity measurements over an extended period,transforming our ice velocity map into a spatially deterministic,temporally average *** all velocity measurements,Thwaites Glacier exhibited a notable spatial variation in the fastest ice flowline and velocity *** distributions on Thwaites Glacier displayed a clear consistency with the positions of subsequent front calving events,offering insights into the instabilities of ice shelves.

关键词： Antarctica ice velocity overestimation correction historical imagery

Physics-Informed Neural Networks with Two Weighted Loss Function Methods for Interactions of Two-Dimensional Oceanic Internal Solitary Waves

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Journal of Systems Science & Complexity 2024年第2期37卷 545-566页

作者： SUN Junchao CHEN Yong TANG Xiaoyan School of Mathematical Sciences Key Laboratory of Mathematics and Engineering Applications(Ministry of Education)&Shanghai Key Laboratory of PMMPEast China Normal UniversityShanghai 200241China College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China

The multiple patterns of internal solitary wave interactions(ISWI)are a complex oceanic *** remote sensing techniques indirectly detect these ISWI,but do not provide information on their detailed structure and ***,the authors considered a three-layer fluid with shear flow and developed a(2+1)Kadomtsev-Petviashvili(KP)model that is capable of describing five types of oceanic ISWI,including O-type,P-type,TO-type,TP-type,and *** learning models,particularly physics-informed neural networks(PINN),are widely used in the field of fluids and internal solitary ***,the authors find that the amplitude of internal solitary waves is much smaller than the wavelength and the ISWI occur at relatively large spatial scales,and these characteristics lead to an imbalance in the loss function of the PINN *** solve this problem,the authors introduce two weighted loss function methods,the fixed weighing and the adaptive weighting methods,to improve the PINN *** successfully simulated the detailed structure and dynamics of ISWI,with simulation results corresponding to the satellite *** particular,the adaptive weighting method can automatically update the weights of different terms in the loss function and outperforms the fixed weighting method in terms of generalization ability.

关键词： Internal solitary wave interactions KP equation PINN method weighted loss function method