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On an Ultra-Dense LEO-Satellite-Based Computing Network Constellation Design 认领 引用 被引量：1
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作者 Yijing Sun Boya Di +1 位作者 Ruoqi Deng Lingyang Song 《Engineering》 SCIE EI CSCD 2025年第11期103-114,共12页
Commercial ultra-dense low-Earth-orbit(LEO)satellite constellations have recently been deployed to provide seamless global Internet services.To improve the satellite network transmission efficiency and provide robust ... Commercial ultra-dense low-Earth-orbit(LEO)satellite constellations have recently been deployed to provide seamless global Internet services.To improve the satellite network transmission efficiency and provide robust wide-coverage computing services for future sixth-generation(6G)users,growing attention has been focused on LEO-satellite-based computing networks,to which ground users can offload computation tasks.However,how to design a LEO satellite constellation for computing networks,while considering discrepancies in the computing requirements of different regions,remains an open question.In this paper,we investigate an ultra-dense LEO-satellite-based computing network to which ground user terminals(UTs)offload part of their computing tasks to satellites.We formulate the ultra-dense constellation design problem as a multi-objective optimization problem(MOOP)to maximize the average coverage rate,transmission capacity,and computational capability,while minimizing the number of satellites.In order to depict the connectivity characteristics of satellite-based computing networks,we propose a terrestrial-satellite connectivity model to determine the coverage rate in different regions.We design a priority-adaptive algorithm to design the optimal inclined-orbit constellation by solving this MOOP.Simulation results verify the accuracy of our theoretical connectivity model and show the optimal constellation deployment,given quality-of-service(QoS)requirements.For the same number of deployed LEO satellites,the proposed constellation outperforms its existing counterparts;in particular,it achieves 25%-45%performance improvements in the average coverage rate. 展开更多
关键词 Low-Earth-orbit satellite constellation Satellite-based computing network Multi-objective optimization
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Satellite-based RAR performance simulation for measuring directional ocean wave spectrum based on SAR inversion spectrum 认领 引用 被引量：2
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作者 REN Lin MAO Zhihua +1 位作者 HUANG Haiqing GONG Fang 《Acta Oceanologica Sinica》 SCIE CAS 2010年第4期13-20,共8页
Some missions have been carried out to measure wave directional spectrum by synthetic aperture radar （SAR） and airborne real aperture radar （RAR） at a low incidence.Both them have their own advantages and limitati... Some missions have been carried out to measure wave directional spectrum by synthetic aperture radar （SAR） and airborne real aperture radar （RAR） at a low incidence.Both them have their own advantages and limitations.Scientists hope that SAR and satellite-based RAR can complement each other for the research on wave properties in the future.For this study,the authors aim to simulate the satellite-based RAR system to validate performance for measuring the directional wave spectrum.The principal measurements are introduced and the simulation methods based on the one developed by Hauser are adopted and slightly modified.To enhance the authenticity of input spectrum and the wave spectrum measuring consistency for SAR and satellite-based RAR,the wave height spectrum inversed from Envisat ASAR data by cross spectrum technology is used as the input spectrum of the simulation system.In the process of simulation,the sea surface,backscattering signal,modulation spectrum and the estimated wave height spectrum are simulated in each look direction.Directional wave spectrum are measured based on the simulated observations from 0 ？ to 360 ？ .From the estimated wave spectrum,it has an 180 ？ ambiguity like SAR,but it has no special high wave number cut off in all the direction.Finally,the estimated spectrum is compared with the input one in terms of the dominant wave wavelength,direction and SWH and the results are promising.The simulation shows that satellite-based RAR should be capable of measuring the directional wave properties.Moreover,it indicates satellite-based RAR basically can measure waves that SAR can measure. 展开更多
关键词 satellite-based RAR directional wave spectrum SAR inversion performance simulation
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A Note on Reviving the Goddard Satellite-Based Surface Turbulent Fluxes (GSSTF) Dataset 认领 引用 被引量：1
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作者 Chung-Lin SHIE Long S. CHIU +7 位作者 Robert ADLER Eric NELKIN I-I LIN Pingping XIE Feng-Chin WANG R. CHOKNGAMWONG William OLSON D. Allen CHU 《Advances in Atmospheric Sciences》 SCIE CAS 2009年第6期1071-1080,共10页
Accurate sea surface flux measurements are crucial for understanding the global water and energy cycles. The oceanic evaporation, which is a major component of the global oceanic fresh water flux, is useful for predic... Accurate sea surface flux measurements are crucial for understanding the global water and energy cycles. The oceanic evaporation, which is a major component of the global oceanic fresh water flux, is useful for predicting oceanic circulation and transport. The global Goddard Satellite-based Surface Turbulent Fluxes Version-2 （GSSTF2; July 1987–December 2000） dateset that was o？cially released in 2001 has been widely used by scientific community for global energy and water cycle research, and regional and short period data analyses. We have recently been funded by NASA to resume processing the GSSTF dataset with an objective of continually producing a uniform dataset of sea surface turbulent fluxes, derived from remote sensing data. The dataset is to be reprocessed and brought up-to-date （GSSTF2b） using improved input datasets such as a recently upgraded NCEP/DOE sea surface temperature reanalysis, and an upgraded surface wind and microwave brightness temperature V6 dataset （Version 6） from the Special Sensor Microwave Imager （SSM/I） produced by Remote Sensing Systems （RSS）. A second new product （GSSTF3） is further proposed with a finer temporal （12-h） and spatial （0.25° × 0.25°） resolution. GSSTF2b （July 1987–December 2008） and GSSTF3 （July 1999–December 2009） will be released for the research community to use by late 2009 and early 2011, respectively. 展开更多
关键词 surface turbulent fluxes global oceanic satellite-based
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Presheath formation and area design limit satellite-based Langmuir probes 认领 引用 被引量：1
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作者 靳琛垚 叶孜崇 +4 位作者 孙海岗 江堤 张炜 徐国盛 王亮 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第12期1-13,共13页
In this article,the effect of the finite conductive surface area of a satellite on the use of satellite-based Langmuir probes is reviewed in light of the basic theory of asymmetric double Langmuir probes(ADLPs).Recent... In this article,the effect of the finite conductive surface area of a satellite on the use of satellite-based Langmuir probes is reviewed in light of the basic theory of asymmetric double Langmuir probes(ADLPs).Recent theoretical and experimental studies have discussed electron sheath/presheath formation and the electron Bohm criterion along with their implications for satellite-based Langmuir probes.The effects predicted by the latest theory of the electron Bohm criterion were not experimentally observed and the experimental results remain supportive of a critical area ratio(AL/AS)crit=(mi/(2.3me))1/2between the probe area ASand the satellite area A_L as conventionally believed.A satellite-based Langmuir probe must satisfy this criterion to physically act as a single Langmuir probe.However,experimental investigations also found that high-energy electrons adversely affect(AL/AS)critand a Langmuir probe's signal quality by giving additional electron current to AL.Based on these results,a number of limitations of the maximum probe area are derived when designing satellite-based Langmuir probes,with consideration of both the aim of the satellite and the plasma where the satellite-based probe works.These proposed measures are expected to only partially alleviate the effect of the inadequate satellite surface area on the application of satellite-based Langmuir probes.Using a larger satellite to carry a Langmuir probe remains the most viable means to obtain precise space plasma parameters. 展开更多
关键词 space plasmas satellite-based Langmuir probe sheath/presheath electric propulsion
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Spatio-temporal variation and propagation direction of coal fire in Jharia Coalfield,India by satellite-based multi-temporal night-time land surface temperature imaging 认领 引用 被引量：6
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作者 Narendra Singh R.S.Chatterjee +1 位作者 Dheeraj Kumar D.C.Panigrahi 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2021年第5期765-778,共14页
In this paper,the spatio-temporal variation and propagation direction of coal fire were studied in the Jharia Coalfield(JCF),India during 2006–2015 through satellite-based night-time land surface temperature(LST)imag... In this paper,the spatio-temporal variation and propagation direction of coal fire were studied in the Jharia Coalfield(JCF),India during 2006–2015 through satellite-based night-time land surface temperature(LST)imaging.The LST was retrieved from Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER)night-time thermal-infrared data by a robust split-window algorithm based on scene-specific regression coefficients,band-specific hybrid emissivity,and night-time atmospheric transmittance.The LST-profile-based coal fire detection algorithm was formulated through statistical analysis of the LST values along multiple transects across diverse coal fire locations in the JCF in order to compute date-specific threshold temperatures for separating thermally-anomalous and background pixels.This algorithm efficiently separates surface fire,subsurface fire,and thermally-anomalous transitional pixels.During the observation period,it was noticed that the coal fire area increased significantly,which resulted from new coal fire at many places owing to extensive opencast-mining operations.It was observed that the fire propagation occurred primarily along the dip direction of the coal seams.At places,lateral-propagation of limited spatial extent was also observed along the strike direction possibly due to spatial continuity of the coal seams along strike.Moreover,the opencast-mining activities carried out during 2009–2015 and the structurally weak planes facilitated the fire propagation. 展开更多
关键词 Satellite-based night-time imaging Land surface temperature Coal fire Spatio-temporal variation Propagation direction Jharia Coalfield
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A Handover Strategy in the LEO Satellite-Based Constellation Networks with ISLs 认领 引用
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作者 LIU Gang GOU Dingyong WU Shiqi 《Journal of Electronic Science and Technology of China》 2003年第1期22-28,共7页
A new handover strategy named minimal-hops handover(MHH) strategy for the lowearth orbit(LEO) satellite constellations networks equipped with inter-satellite links(ISLs) is proposed.MHH strategy,which is based on the ... A new handover strategy named minimal-hops handover(MHH) strategy for the lowearth orbit(LEO) satellite constellations networks equipped with inter-satellite links(ISLs) is proposed.MHH strategy,which is based on the hops of the end-to-end connection paths and makes good use of theregularity of the constellation network topology,can appropriately combine the handover procedure withrouting and efficiently solve the inter-satellite handover issue.Moreover,MHH strategy can providequality of services(QoS) guarantees to some extent.The system performances of the MHH strategy,suchas time propagation delay and handover frequency,are evaluated and compared with that of otherprevious strategies.The simulation results show that MHH strategy performs better than other previoushandover strategies. 展开更多
关键词 low earth orbit(LEO)satellite-based constellation networks time propagation delay quality of services(QoS) inter-satellite link(ISL) inter-satellite handover
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Enhancing satellite-based emergency mapping:ldentifying wildfires through geo-social media analysis 认领 引用 被引量：1
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作者 Sebastian Schmidt Monika Friedemann +3 位作者 David Hanny Bernd Resch Torsten Riedlinger Martin Mühlbauer 《Big Earth Data》 EI CSCD 2025年第3期389-411,共23页
When a disaster emerges,timely acquisition of information is crucial for a rapid situation assessment.Although automation in the stan-dard satellite-based emergency mapping workflow has been advanced,delays still occu... When a disaster emerges,timely acquisition of information is crucial for a rapid situation assessment.Although automation in the stan-dard satellite-based emergency mapping workflow has been advanced,delays still occur at crucial steps.In order to speed up the provision of satellite-based crisis products to emergency man-agers,this paper proposes a geo-social media-based approach that detects disaster events based on the spatio-temporal analysis of georeferenced,disaster-related Tweets.The proposed methodol-ogy is validated on the basis of two use cases:wildfires in Chile and British Columbia.The results show the general ability of Twitter to forecast events several days in advance,at least for the Chile use case.However,there are large spatial differences,as there is a correlation between population density and the reliability of Twitter data.Consequently,only few meaningful alerts could be generated for British Columbia,an area with very low population numbers. 展开更多
关键词 Disaster alerts satellite-based emergency mapping Twitter RoBERTa
Re-understanding of land surface albedo and related terms in satellite-based retrievals 认领 引用 被引量：4
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作者 Yanmin Shuai Latipa Tuerhanjiang +6 位作者 Congying Shao Feng Gao Yuyu Zhou Donghui Xie Tao Liu Ji Liang Nan Chu 《Big Earth Data》 EI 2020年第1期45-67,共23页
Land surface albedo is a critical variable in determining surface energy balance,and regulating climate and ecosystem processes through feedback mechanisms.Therefore,climatic modelers and radiative monitoring require ... Land surface albedo is a critical variable in determining surface energy balance,and regulating climate and ecosystem processes through feedback mechanisms.Therefore,climatic modelers and radiative monitoring require accurate estimates of land surface albedo.With the instrument development,algorithm upgrade,spectral-band-adjustment in wavelength center or band width,and the increasing distinct requirement from diversified communities,various albedo terms have been generated in related satellite-based products.The lack of understanding on the divergence of these terminologies can introduce potential considerable errors in the subsequent applications,or an elevated probability to invert the deduced conclusion.We surveyed the basic concepts of reflectance quantities,retrieval strategies,and models developed since the 1970s,and discuss both strength and opportunity for improvements on land surface albedo extraction,and product generation.In addition,we exemplified the difference of albedo terms using the daily MODIS product(MCD43A)to emphasize the potential risk of the ambiguous usage,over typical IGBP land covers in Northern Kazakhstan.Our investigation shows that relative differences among various albedo terms can reach up to 181%and 50%,while 0.266 and 0.118 of absolute variance respectively in the narrow and broad-band surface albedo,which illuminated cautions against the ambiguous understanding of albedo terminologies or erroneous usage of albedo products. 展开更多
关键词 Surface albedo BRDF satellite-based albedo product hemispheric reflectance
Improved Assimilation of Fengyun-3 Satellite-Based Snow Cover Fraction in Northeastern China 认领 引用 被引量：2
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作者 Shuai ZHANG Chunxiang SHI +1 位作者 Runping SHEN Jie WU 《Journal of Meteorological Research》 SCIE CSCD 2019年第5期960-975,共16页
Assimilation of snow cover is an important method to improve the accuracy of snow simulation. However, the effects of snow assimilation are poor because satellite observed snow cover data contain erroneous information... Assimilation of snow cover is an important method to improve the accuracy of snow simulation. However, the effects of snow assimilation are poor because satellite observed snow cover data contain erroneous information, such as cloud contamination. In this paper, an improved approach is proposed to reduce the effects of observational errors during assimilation of snow cover fraction acquired by the Fengyun-3(FY-3) satellite in northeastern China. A snow depth constraint was imposed on quality control of a snow depth product from a microwave radiation imager. The assimilation experiments were carried out before and after quality control(denoted as SCFDA and SCFDA_WSD, respectively). The snow cover fraction results were evaluated against the Moderate Resolution Imaging Spectroradiometer(MODIS) snow cover products. When assimilating the snow cover fraction with the snow depth constraint(i.e., SCFDA_WSD), substantially larger improvement was obtained than that without such a constraint/quality control(SCFDA), and the deviation and root mean square error of the snow cover fraction were significantly reduced.The assimilation performance was also evaluated against in-situ snow depth observations. The SCFDA_WSD also showed greater improvements during the snow accumulation and snowmelt periods than the SCFDA. The SCFDA_WSD improvements in woodland and shrubland were the most obvious. At different altitudes, the effects of the SCFDA_WSD were basically equivalent, and the deeper the snow depth was, the better the effect. In addition, the SCFDA_WSD method was found in close agreement with the observations during a sudden snowfall event. 展开更多
关键词 snow cover assimilation FY-3 satellite-based snow products snow cover fraction
Satellite integrity monitoring for satellite-based augmentation system:an improved covariance-based method 认领 引用 被引量：6
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作者 Shuaiyong Zheng Mengzhi Gao +2 位作者 Zhigang Huang Xiaoqin Jin Kun Li 《Satellite Navigation》 CSCD 2022年第1期74-84,I0003,共11页
Satellite integrity monitoring is vital to satellite-based augmentation systems,and can provide the confdence of the diferential corrections for each monitored satellite satisfying the stringent safety-of-life require... Satellite integrity monitoring is vital to satellite-based augmentation systems,and can provide the confdence of the diferential corrections for each monitored satellite satisfying the stringent safety-of-life requirements.Satellite integrity information includes the user diferential range error and the clock-ephemeris covariance which are used to deduce integrity probability.However,the existing direct statistic methods sufer from a low integrity bounding percentage.To address this problem,we develop an improved covariance-based method to determine satellite integrity information and evaluate its performance in the range domain and position domain.Compared with the direct statistic method,the integrity bounding percentage is improved by 24.91%and the availability by 5.63%.Compared with the covariance-based method,the convergence rate for the user diferential range error is improved by 8.04%.The proposed method is useful for the satellite integrity monitoring of a satellite-based augmentation system. 展开更多
关键词 Clock-ephemeris covariance matrix Groove model Satellite-based augmentation system Scale model User diferential range error
Design of Navigation Message Authentication for BDSBAS System 认领 引用
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作者 Chen Xiao Tian Xiang +2 位作者 Luo Ruidan Liu Ting Wu Haitao 《China Communications》 SCIE EI CSCD 2026年第1期189-203,共15页
The satellite-based augmentation system(SBAS)provides differential and integrity augmentation services for life safety fields of aviation and navigation.However,the signal structure of SBAS is public,which incurs a ri... The satellite-based augmentation system(SBAS)provides differential and integrity augmentation services for life safety fields of aviation and navigation.However,the signal structure of SBAS is public,which incurs a risk of spoofing attacks.To improve the anti-spoofing capability of the SBAS,European Union and the United States conduct research on navigation message authentication,and promote the standardization of SBAS message authentication.For the development of Beidou satellite-based augmentation system(BDSBAS),this paper proposes navigation message authentication based on the Chinese commercial cryptographic standards.Firstly,this paper expounds the architecture and principles of the SBAS message authentication,and then carries out the design of timed efficient streaming losstolerant authentication scheme(TESLA)and elliptic curve digital signature algorithm(ECDSA)authentication schemes based on Chinese commercial cryptographic standards,message arrangement and the design of over-the-air rekeying(OTAR)message.Finally,this paper conducts a theoretical analysis of the time between authentications(TBA)and maximum authentication latency(MAL)for L5 TESLA-I and L5 ECDSA-Q,and further simulates the reception time of OTAR message,TBA and MAL from the aspects of OTAR message weight and demodulation error rate.The simulation results can provide theoretical supports for the standardization of BDSBAS message authentication. 展开更多
关键词 Beidou satellite-based augmentation system ECDSA message authentication satellite navigation TESLA
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Estimating evapotranspiration at high spatio-temporal resolution based on the Bayesian model averaging method in Baoding Plain, China 认领 引用
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作者 Se Chai Jiang-zhou Xia +4 位作者 Yong-hong Hao Cui-ting Qi Juan Zhang Yang Chen Hui-feng Yang 《Journal of Groundwater Science and Engineering》 2026年第2期233-251,共19页
Evapotranspiration(ET)is a core parameter of the hydrology and carbon cycles,and its accurate estimation is crucial for water resource management.Satellite-based ET products provide an effective means for large-scale ... Evapotranspiration(ET)is a core parameter of the hydrology and carbon cycles,and its accurate estimation is crucial for water resource management.Satellite-based ET products provide an effective means for large-scale monitoring.However,due to limitations in the spatial and temporal resolution,the use of these products at regional and field scales is limited.In this study,daily ET in the Baoding Plain—a key groundwater resource recharge area—was estimated at a 500 m spatial resolution using the Bayesian Model Averaging(BMA)method.The model was driven by a synthesis of remote sensing datasets,reanalysis products,and interpolated data from meteorological stations.Validation results from in-situ observations indicated that the BMA ET had better performance(R=0.83,RMSE=1.25 mm/d)than each model in the BMA scheme.The spatiotemporal analysis revealed that the average annual BMA ET in the Baoding Plain was 683 mm/year from 2000 to 2019.Seasonal and monthly variations in the BMA ET captured the irrigation and water consumption patterns of the local crop rotation systems.A significant increasing trend of BMA ET(2.40 mm/year2)was observed in the Baoding Plain over the study period.At the regional scale,ET over more than 50%of the plain exhibited a significant positive trend.Further analysis identified water availability,solar radiation,and temperature as the primary drivers of ET variation.The BMA ET product generated in this study is characterized by high spatiotemporal resolution and accuracy.This reliable,highresolution dataset offers valuable support for precision agricultural water management and hydrological studies,including groundwater investigations,in this predominantly agricultural region. 展开更多
关键词 Evapotranspiration Satellite-based model Random Forest model Climate change Water resources
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Hydrological Simulation Using TRMM and CHIRPS Precipitation Estimates in the Lower Lancang-Mekong River Basin 认领 引用 被引量：3
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作者 LUO Xian WU Wenqi +2 位作者 HE Daming LI Yungang JI Xuan 《Chinese Geographical Science》 SCIE CSCD 2019年第1期13-25,共13页
Satellite-based products with high spatial and temporal resolution provide useful precipitation information for data-sparse or ungauged large-scale watersheds. In the Lower Lancang-Mekong River Basin, rainfall station... Satellite-based products with high spatial and temporal resolution provide useful precipitation information for data-sparse or ungauged large-scale watersheds. In the Lower Lancang-Mekong River Basin, rainfall stations are sparse and unevenly distributed, and the transboundary characteristic makes the collection of precipitation data more difficult, which has restricted hydrological processes simulation. In this study, daily precipitation data from four datasets(gauge observations, inverse distance weighted(IDW) data, Tropical Rainfall Measuring Mission(TRMM) estimates, and Climate Hazards Group InfraRed Precipitation with Stations(CHIRPS) estimates), were applied to drive the Soil and Water Assessment Tool(SWAT) model, and then their capability for hydrological simulation in the Lower Lancang-Mekong River Basin were examined. TRMM and CHIRPS data showed good performances on precipitation estimation in the Lower Lancang-Mekong River Basin, with the better performance for TRMM product. The Nash-Sutcliffe efficiency(NSE) values of gauge, IDW, TRMM, and CHIRPS simulations during the calibration period were 0.87, 0.86, 0.95, and 0.93 for monthly flow, respectively, and those for daily flow were 0.75, 0.77, 0.86, and 0.84, respectively. TRMM and CHIRPS data were superior to rain gauge and IDW data for driving the hydrological model, and TRMM data produced the best simulation performance. Satellite-based precipitation estimates could be suitable data sources when simulating hydrological processes for large data-poor or ungauged watersheds, especially in international river basins for which precipitation observations are difficult to collect. CHIRPS data provide long precipitation time series from 1981 to near present and thus could be used as an alternative precipitation input for hydrological simulation, especially for the period without TRMM data. For satellite-based precipitation products, the differences in the occurrence frequencies and amounts of precipitation with different intensities would affect simulation results of water balance components, which should be comprehensively considered in water resources estimation and planning. 展开更多
关键词 hydrological simulation satellite-based precipitation estimates spatial distribution of precipitation international river the Lower Lancang-Mekong River Basin
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Progress of Geodesy Related Ionosphere from Chinese Scientists in the Period of 2019—2023 认领 引用 被引量：6
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作者 Zishen LI Ningbo WANG +5 位作者 Ang LIU Ang LI Heng YANG Dongshen ZHAO Xiaodong REN Andong HU 《Journal of Geodesy and Geoinformation Science》 CSCD 2023年第3期115-123,共9页
The ionosphere is the ionized part of the upper atmosphere of the Earth,which plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere.It influences radio propagation significan... The ionosphere is the ionized part of the upper atmosphere of the Earth,which plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere.It influences radio propagation significantly,such as the Global Navigation Satellite System(GNSS).Meanwhile,the GNSS is also an essential technique for sensing the variation of ionosphere.During the years of 2019—2023,a large number of Chinese geodesy scientists devoted much efforts to the geodesy related ionosphere.Due to the very limited length,the achievements are carried out from the following six aspects,including:①The ionospheric correction models for BDS and BDSBAS;②Real-time global ionospheric monitoring and modeling;③The ionospheric 2D and 3D modeling based on GNSS and LEO satellites;④The ionospheric prediction based on artificial intelligence;⑤The monitoring and mitigation of ionospheric disturbances for GNSS users;⑥The ionospheric related data products and classical applications. 展开更多
关键词 ionosphere Global Navigation Satellite System(GNSS) BDS satellite-based augmentation system
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Improving the accuracy of precipitation estimates in a typical inland arid area of China using a dynamic Bayesian model averaging approach 认领 引用 被引量：1
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作者 XU Wenjie DING Jianli +2 位作者 BAO Qingling WANG Jinjie XU Kun 《Journal of Arid Land》 SCIE CSCD 2024年第3期331-354,共24页
Xinjiang Uygur Autonomous Region is a typical inland arid area in China with a sparse and uneven distribution of meteorological stations,limited access to precipitation data,and significant water scarcity.Evaluating a... Xinjiang Uygur Autonomous Region is a typical inland arid area in China with a sparse and uneven distribution of meteorological stations,limited access to precipitation data,and significant water scarcity.Evaluating and integrating precipitation datasets from different sources to accurately characterize precipitation patterns has become a challenge to provide more accurate and alternative precipitation information for the region,which can even improve the performance of hydrological modelling.This study evaluated the applicability of widely used five satellite-based precipitation products(Climate Hazards Group InfraRed Precipitation with Station(CHIRPS),China Meteorological Forcing Dataset(CMFD),Climate Prediction Center morphing method(CMORPH),Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Record(PERSIANN-CDR),and Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis(TMPA))and a reanalysis precipitation dataset(ECMWF Reanalysis v5-Land Dataset(ERA5-Land))in Xinjiang using ground-based observational precipitation data from a limited number of meteorological stations.Based on this assessment,we proposed a framework that integrated different precipitation datasets with varying spatial resolutions using a dynamic Bayesian model averaging(DBMA)approach,the expectation-maximization method,and the ordinary Kriging interpolation method.The daily precipitation data merged using the DBMA approach exhibited distinct spatiotemporal variability,with an outstanding performance,as indicated by low root mean square error(RMSE=1.40 mm/d)and high Person's correlation coefficient(CC=0.67).Compared with the traditional simple model averaging(SMA)and individual product data,although the DBMA-fused precipitation data were slightly lower than the best precipitation product(CMFD),the overall performance of DBMA was more robust.The error analysis between DBMA-fused precipitation dataset and the more advanced Integrated Multi-satellite Retrievals for Global Precipitation Measurement Final(IMERG-F)precipitation product,as well as hydrological simulations in the Ebinur Lake Basin,further demonstrated the superior performance of DBMA-fused precipitation dataset in the entire Xinjiang region.The proposed framework for solving the fusion problem of multi-source precipitation data with different spatial resolutions is feasible for application in inland arid areas,and aids in obtaining more accurate regional hydrological information and improving regional water resources management capabilities and meteorological research in these regions. 展开更多
关键词 precipitation estimates satellite-based and reanalysis precipitation dynamic Bayesian model averaging streamflow simulation Ebinur Lake Basin Xinjiang
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The improved model of estimating global whitecap coverage based on satellite data 认领 引用 被引量：4
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作者 REN Danqin HUA Feng +1 位作者 YANG Yongzeng SUN Baonan 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第5期66-72,共7页
The pro and con of whitecap parameterizations and a statistical wave breaking model are discussed. An improved model is derived by combining satellite-based parameterization and the wave breaking model. The appropriat... The pro and con of whitecap parameterizations and a statistical wave breaking model are discussed. An improved model is derived by combining satellite-based parameterization and the wave breaking model. The appropriate constants for the general wave state are obtained by considering the breaking condition of the wave slope and fitting with the satellite-based parameterization. The result is close to the constants based on the whitecap data from Monahan. Comparing with satellite-based data and the original model＇s results, the improved model＇s results are consistent with satellite-based data and previous studies. The global seasonal distributions of the whitecap coverage averaged from 1998 to 2008 are presented. Spatial and seasonal features of the whitecap coverage are analyzed. 展开更多
关键词 whitecap coverage statistical wave breaking model satellite-based parameterization
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Seasonal Wind Characteristics and Prospects of Wind Energy Conversion Systems for Water Production in the Far North Region of Cameroon 认领 引用 被引量：1
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作者 Dieudonné Kaoga Kidmo Bachirou Bogno +1 位作者 Kodji Deli Deli Goron 《Smart Grid and Renewable Energy》 2020年第9期127-164,共38页
This study aimed at investigating the characteristics of the wind power resource in the Far North Region of Cameroon (FNR), based on modelling of daily long-term satellite-derived data (2005-2020) and in-situ wind mea... This study aimed at investigating the characteristics of the wind power resource in the Far North Region of Cameroon (FNR), based on modelling of daily long-term satellite-derived data (2005-2020) and in-situ wind measurements data (1987-2020). Five different reliable statistical indicators assessed the accuracy level for the goodness-of-fit tests of satellite-derived data. The two-parameter Weibull distribution function using the energy factor method described the statistical distribution of wind speed and investigated the characteristics of the wind power resource. Six 10-kW pitch-controlled wind turbines (WT) evaluated the power output, energy and water produced. A 50 m pumping head was considered to estimate seasonal variations of volumetric flow rates and costs of water produced. The results revealed that the wind resource in FNR is suitable only for wind pumping applications. Based on the hydraulic requirements for wind pumps, mechanical wind pumping system can be the most cost-effective option of wind pumping technologies in FNR. However, based on the estimated capacity factors of selected WT, wind electric pumping system can be acceptable for only four out of twenty-one sites in FNR. 展开更多
关键词 In Situ Wind Measurements Mechanical Wind Pumping Wind Electrical Pumping Satellite-Based Wind Resource Wind Energy Far North Cameroon
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Principle and performance of BDSBAS and PPP-B2b of BDS-3 认领 引用 被引量：50
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作者 Yuanxi Yang Qun Ding +3 位作者 Weiguang Gao Jinlong Li Yangyin Xu Bijiao Sun 《Satellite Navigation》 CSCD 2022年第1期25-33,I0002,共9页
Within the framework of diferential augmentation,this paper introduces the basic technical framework and performance of the BeiDou Global Navigation Satellite System(BDS-3)Satellite-Based Augmentation System(BDSBAS),i... Within the framework of diferential augmentation,this paper introduces the basic technical framework and performance of the BeiDou Global Navigation Satellite System(BDS-3)Satellite-Based Augmentation System(BDSBAS),including orbit products,satellite clock ofset products,ionosphere and its integrity performance.The basic principle of BDS-3 Precise Point Positioning(PPP-B2b)is expounded,the similarities and diferences between the PPP service provided by BDS-3 and International Global Navigation Satellite System(GNSS)Service(IGS)are discussed,and the limitations of PPP-B2b are analyzed.Since both the BDSBAS and PPP-B2b utilize a ground monitoring station network to determine the satellite orbits and clock ofset corrections,and broadcast diferential corrections through the three Geostationary Orbit(GEO)satellites of BDS-3,the feasibility of the co-construction of BDSBAS and PPP-B2b is analyzed,strategies for the infrastructure sharing and correction broadcasting are presented,and the infuences of BDSBAS correction broadcasting strategy adjustment are evaluated.In addition,it assesses the possibility of broadcasting diferential corrections through the Inclined Geosynchronous Orbit(IGSO)satellites of BDS-3,and the feasibility of augmenting satellite navigation with Low Earth Orbit(LEO)satellites. 展开更多
关键词 Satellite-based augmentation Precise point positioning Precise orbit Precise clock ofset Ionospheric model
Comparing simulated atmospheric carbon dioxide concentration with GOSAT retrievals 认领 引用 被引量：5
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作者 张慧芳 陈报章 +6 位作者 许光 严建武 车明亮 陈婧 房世峰 林晓凤 孙少波 《Science Bulletin》 SCIE CAS CSCD 2015年第3期380-386,I0002,共7页
Satellite observations of atmospheric carbon dioxide （CO2） provide a useful way to improve the understanding of global carbon cycling. In this paper, we present a comparison between simulated CO2 concentrations from... Satellite observations of atmospheric carbon dioxide （CO2） provide a useful way to improve the understanding of global carbon cycling. In this paper, we present a comparison between simulated CO2 concentrations from an inversion model of the CarbonTracker Data Assimilation System （CTDAS） and satellite-based CO2 measurements of column-averaged dry air mole fraction （denoted XCO2） derived from version 3.3 Atmospheric CO2 Observations from Space retrievals of the Greenhouse Gases Observing SATellite （ACOS-GOSAT） L2 data products. We examine the differences of CTDAS and GOSAT to provide important guidance for the further investigation of CTDAS in order to quantify the corre- sponding flux estimates with satellite-based CO2 observations. We find that the mean point-by-point difference （CTDAS-GOSAT） between CTDAS and GOSAT XCO2 is -0.11 4-1.81 ppm, with a high agreement （correlation r = 0.77, P 〈 0.05） over the studied period. The latitudinal zonal variations of CTDAS and GOSAT are in general agreement with clear seasonal fluctuations. The major exception occurs in the zonal band of 0°-15°N where the difference is approximately 4 ppm, indicating that large uncertainty may exist in the assimilated CO2 for the low- latitude region of the Northem Hemisphere （NH）. Additionally, we find that the hemispherical/continental differences between CTDAS and GOSAT are typically less than 1 ppm, but obvious discrepancies occur in different hemispheres/continents, with high consistency （point-by-point correlation r = 0.79, P 〈 0.05） in the NH and a weak correlation （point-by-point correlation r = 0.65, P 〈 0.05） in the Southern Hemisphere. Overall, the difference of CTDAS and GOSAT is small, and the comparison of CTDAS and GOSAT will further instruct the inverse modeling of CO2 fluxes using GOSAT. 展开更多
关键词 CTDAS model Satellite-based CO2 concentration GOSAT Comparison Inversion method
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Estimation method of SBAS dual-frequency range error integrity parameter 认领 引用 被引量：13
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作者 Bo Shao Qun Ding Xianbing Wu 《Satellite Navigation》 SCIE EI 2020年第1期93-100,共8页
The development of a dual-frequency multi-constellation satellite-based augmentation system(DFMC SBAS)is in progress worldwide.The broadcasted dual-frequency range error(DFRE)integrity parameter reflects the effects o... The development of a dual-frequency multi-constellation satellite-based augmentation system(DFMC SBAS)is in progress worldwide.The broadcasted dual-frequency range error(DFRE)integrity parameter reflects the effects of satellite ephemeris and clock corrections.A user uses the DFRE to calculate the protection level and then determines whether the DFMC SBAS service satisfies the requirements of the current flight phase.However,the calculation of the DFRE has not been reported.Herein,a DFRE estimation method is proposed based on the projection method.Using the ephemeris-clock covariance matrix of each satellite,the maximal projection direction was solved,and the projection of the covariance matrix on this direction was used as the DFRE to form an envelope for the maximal corrected error.Results show that the DFRE can form an envelope of the maximal corrected error with a set probability,and the integrity performance in the user segment satisfies the Category I precision approach requirement. 展开更多
关键词 Satellite-based augmentation system Dual-frequency multi-constellation Dual-frequency range error Integrity
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