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The Soft X-ray Imager(SXI)on the SMILE Mission

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Earth and Planetary Physics 2024年第1期8卷 5-14页

作者： S.Sembay A.L.Alme D.Agnolon T.Arnold A.Beardmore A.Belén Balado Margeli C.Bicknell C.Bouldin G.Branduardi-Raymont T.Crawford J.P.Breuer T.Buggey G.Butcher R.Canchal J.A.Carter A.Cheney Y.Collado-Vega H.Connor T.Crawford N.Eaton C.Feldman C.Forsyth T.Frantzen G.Galgóczi J.Garcia G.Y.Genov C.Gordillo H-P.Gröbelbauer M.Guedel Y.Guo M.Hailey D.Hall R.Hampson J.Hasiba O.Hetherington A.Holland S-Y.Hsieh M.W.J.Hubbard H.Jeszenszky M.Jones T.Kennedy K.Koch-Mehrin S.Kögl S.Krucker K.D.Kuntz C.Lakin G.Laky O.Lylund A.Martindale J.Miguel Mas Hesse R.Nakamura K.Oksavik N.Østgaard H.Ottacher R.Ottensamer C.Pagani S.Parsons P.Patel J.Pearson G.Peikert F.S.Porter T.Pouliantis B.H.Qureshi W.Raab G.Randal A.M.Read N.M.M.Roque M.E.Rostad C.Runciman S.Sachdev A.Samsonov M.Soman D.Sibeck S.Smit J.Søndergaard R.Speight S.Stavland M.Steller TianRan Sun J.Thornhill W.Thomas K.Ullaland B.Walsh D.Walton C.Wang S.Yang School of Physics and Astronomy University of LeicesterLeicesterLE17RHUK space Park Leicester University of LeicesterLeicesterLE17RHUK Mullard space Science Laboratory University College LondonDorkingRH56NTUK Centre for Electronic Imaging Open UniversityMilton KeynesMK76 AAUK Birkeland Centre for space Science Department of Physics and TechnologyUniv.of BergenN-5007 BergenNorway University of Vienna A-1010 ViennaAustria space Research Institute Austrian Academy of SciencesA-8042 GrazAustria national Institute of Aerospace Technology MadridSpain ESTEC European Space Agency2201 AZ NoordwijkNetherlands State Key Laboratory of space Weather National Space Science CentreBeijing 100190China University of Applied Sciences and Arts Northwestern Switzerland CH-5210 WindischSwitzerland Koegl space GmbH CH-8157 DielsdorfSwitzerland space Acoustics GmbH CH-8157 DielsdorfSwitzerland Zurich University of Applied Sciences 8400 WinterhurSwitzerland Genov Solutions N-5172 LoddefjordNorway STM Engineering N-5165 LaksevagNorway John Hopkins University Applied Physics Laboratory MD 20723USA nasa/Goddard space Flight Centre MD 20771USA Center for space Physics Boston UniversityBostonMA 02215USA Department of Theoretical Physics and Astrophysics Masaryk University60177 BrnoCzech Republic Institute of Physics E¨otvo¨s Lor´and University1053 BudapestHungary Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100045China Centro de Astrobiologia(CAB) CSIC-INTAMadridSpain

The Soft X-ray Imager(SXI)is part of the scientific payload of the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)*** is a joint science mission between the European space Agency(ESA)and the Chinese Academy of Sciences(CAS)and is due for launch in *** is a compact X-ray telescope with a wide field-of-view(FOV)capable of encompassing large portions of Earth’s magnetosphere from the vantage point of the SMILE *** is sensitive to the soft X-rays produced by the Solar Wind Charge eXchange(SWCX)process produced when heavy ions of solar wind origin interact with neutral particles in Earth’s *** provides a mechanism for boundary detection within the magnetosphere,such as the position of Earth’s magnetopause,because the solar wind heavy ions have a very low density in regions of closed magnetic field *** sensitivity of the SXI is such that it can potentially track movements of the magnetopause on timescales of a few minutes and the orbit of SMILE will enable such movements to be tracked for segments lasting many *** is led by the University of Leicester in the United Kingdom(UK)with collaborating organisations on hardware,software and science support within the UK,Europe,China and the United States.

关键词： Soft X-ray Imaging micropore optics large area CCD

Long-term Integration Ability of the Submillimeter Wave Astronomy Satellite(SWAS)Spectral Line Receivers

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Research in Astronomy and Astrophysics 2024年第6期24卷 315-322页

作者： Bing-Ru Wang Di Li Paul F.Goldsmith Jingwen Wu Chao-Wei Tsai Rudolf Schieder Gary J.Melnick national Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Research Center for Astronomical Computing Zhejiang LaboratoryHangzhou 311100China Jet Propulsion Laboratory California Institute of TechnologyPasadenaCA 91109USA Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China KOSMA I.Physik.InstitutUniversität zu KölnZülpicher Str.7750937 KölnGermany Center for Astrophysics|Harvard&Smithsonian 60 Garden StreetMS 66CambridgeMA 02138USA

The Submillimeter Wave Astronomy Satellite(SWAS)was the first space telescope capable of high spectral resolution observations of terahertz spectral *** have investigated the integration ability of its two receivers and spectrometer during five and a half years of on-orbit *** CI,O_(2),H_(2)O,and^(13)CO spectra taken toward all observed Galactic sources were *** present results are based on spectra with a total integration time of up to 2.72×10~4hr(■10~8s).The noise in the spectra is generally consistent with that expected from the radiometer equation,without any sign of approaching a noise *** noise performance reflects the extremely stable performance of the passively cooled front end as well as other relevant components in the SWAS instrument throughout its mission lifetime.

关键词： telescopes space vehicles:instruments instrumentation:miscellaneous ISM:lines and bands

On the longitudinal shifts of the Agulhas retroflection point

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Acta Oceanologica Sinica 2024年第5期43卷 16-29页

作者： Weiwei Zhang Xiaoyi Yang Wei Zhuang Xiaohai Yan State Key Laboratory of Marine Environmental Science College of Ocean and Earth SciencesXiamen UniversityXiamen 361002China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China Center for Remote Sensing College of EarthOcean and EnvironmentUniversity of DelawareNewarkDE 19716USA Joint Center for Remote Sensing University of Delaware-Xiamen UniversityNewarkDE 19716USA and Xiamen 361002China

The Agulhas system is the strongest western boundary current system in the Southern Hemisphere and plays an important role in modulating the Indian-to-Atlantic Ocean water exchange by the Agulhas *** is difficult to measure in situ transport of the Agulhas leakage as well as the Agulhas retroflection position due to their intermittent *** this study,an innovative kinematic algorithm was designed and applied to the gridded altimeter observational data,to ascertain the longitudinal position of Agulhas retroflection,the stability of Agulhas jet stream,as well as its *** results show that the east-west shift of retroflection is related neither to the strength of Agulhas current nor to its *** analysis uncovers the connection between the westward extension of Agulhas jet stream and an anomalous cyclonic circulation at its northern side,which is likely attributed to the local wind stress curl *** confirm the effect of local wind forcing on the east-west shift of retroflection,numerical sensitivity experiments were *** results show that the local wind stress can induce a similar longitudinal shift of the retroflection as altimetry *** statistical and case study indicates that whether an Agulhas ring can continuously migrate westward to the Atlantic Ocean or re-merge into the main flow depends on the retroflection ***,the westward retroflection may contribute to a stronger Agulhas leakage than the eastward retroflection.

关键词： Agulhas system Agulhas leakage retroflection position local wind stress curl

Construction and Optimization of TRNG Based Substitution Boxes for Block Encryption Algorithms

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Computers, Materials & Continua 2022年第11期73卷 2679-2696页

作者： Muhammad Fahad Khan Khalid Saleem Mohammed Alotaibi Mohammad Mazyad Hazzazi Eid Rehman Aaqif Afzaal Abbasi Muhammad Asif Gondal Quaid e Azam University Islamabad45320Pakistan Foundation University Islamabad Islamabad44000Pakistan College of Business administration University of TabukTabuk71491Saudi Arabia Department of Mathematics College of ScienceKing Khalid UniversityAbha61413Saudi Arabia Department of Mathematics and Sciences Dhofar UniversitySalalah211Oman

Internet of Things is an ecosystem of interconnected devices that are accessible through the *** recent research focuses on adding more smartness and intelligence to these edge *** makes them susceptible to various kinds of security *** edge devices rely on cryptographic techniques to encrypt the pre-processed data collected from the sensors deployed in the *** this regard,block cipher has been one of the most reliable options through which data security is *** strength of block encryption algorithms against different attacks is dependent on its nonlinear primitive which is called Substitution *** the design of S-boxes mainly algebraic and chaos-based techniques are used but researchers also found various weaknesses in these *** the other side,literature endorse the true random numbers for information security due to the reason that,true random numbers are purely *** this paper firstly a natural dynamical phenomenon is utilized for the generation of true random numbers based ***,a systematic literature review was conducted to know which metaheuristic optimization technique is highly adopted in the current decade for the optimization of *** on the outcome of Systematic Literature Review(SLR),genetic algorithm is chosen for the optimization of *** results of our method validate that the proposed dynamic S-boxes are effective for the block ***,our results showed that the proposed substitution boxes achieve better cryptographic strength as compared with state-of-the-art techniques.

关键词： IoT security sensors data encryption substitution box generation True Random Number Generators(TRNG) heuristic optimization genetic algorithm

The mathematical weighting of GNSS observations based on different types of receivers/antennas and environmental conditions

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Geodesy and Geodynamics 2023年第5期14卷 521-540页

作者： Kamal Parvazi Saeed Farzaneh Abdolreza Safari School of Surveying and Geospatial Engineering College of EngineeringUniversity of TehranNorth Kargar Street***TehranIran

Stochastic models play an important role in achieving high accuracy in positioning,the ideal estimator in the least-squares(LS)can be obtained only by using the suitable stochastic *** study investigates the role of variance component estimation(VCE)in the LS method for Precise Point Positioning(PPP).This estimation is performed by considering the ionospheric-free(IF)functional model for code and the phase observation of Global Positioning System(GPS).The strategy for estimating the accuracy of these observations was evaluated to check the effect of the stochastic model in four modes:a)antenna type,b)receiver type,c)the tropospheric effect,and d)the ionosphere *** results show that using empirical variance for code and phase observations in some cases caused erroneous estimation of unknown components in the PPP *** is because a constant empirical variance may not be suitable for various receivers and antennas under different *** were compared in two cases using the stochastic model of nominal weight and weight estimated by *** position error difference for the east-west,north-south,and height components was 1.5 cm,4 mm,and 1.8 cm,***,weight estimation with LS-VCE can provide more appropriate ***,the convergence time based on four elevation-dependent models was evaluated using nominal weight and LS-VCE *** to the results,the LS-VCE has a higher convergence rate than the nominal *** weight estimation using LS-VCE improves the convergence time in four elevation-dependent models by 11,13,12,and 9 min,respectively.

关键词： Stochastic model Global positioning system Variance component estimation Least-squares Precise point positioning Elevation-dependent model

Variation of XCO_(2) anomaly patterns in the Middle East from OCO-2 satellite data

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International Journal of Digital Earth 2022年第1期15卷 1219-1235页

作者： Foroogh Golkar Seyed Mohsen Mousavi Department of Water Engineering&Oceanic and Atmospheric Research Centre College of AgricultureShiraz UniversityShirazIran Department of Environmental Planning and Design Shahid Beheshti UniversityTehranIran

The anthropogenic CO_(2) emission is contributed to the rapid increase in CO_(2) *** the current study the anthropogenic CO_(2) emission in the Middle East(ME)is investigated using 6 years columnaveraged CO_(2) dry air mole fraction(XCO_(2))observation from Orbiting Carbon Observatory-2(OCO-2)*** this way,the XCO_(2) anomaly(DXCO_(2))as the detrended and deseasonalized term of OCO-2XCO_(2) product,was computed and compared to provide the direct spacebased anthropogenic CO_(2) emission *** a result,the high positive and negative DXCO_(2) values have corresponded to the major sources such as oil and gas industries,and growing seasons over ME,***,the Open-source Data Inventory for Anthropogenic CO_(2)(ODIAC)emission and the gross primary productivity(GPP)were utilized in exploring the DXCO_(2) relation with human and natural driving *** results showed the capability of DXCO_(2) maps in detecting CO_(2) emission fluctuations in defined periods were detectible in daily to annual *** simplicity and accuracy of the method in detecting the man-made and natural driving factors including the main industrial areas,megacities,or local changes due to COVID-19 pandemic or geopolitical situations as well as the vegetation absorption and biomass burning is the key point that provides the environmental managers and policymakers with valuable and accessible information to control and ultimately reduce the CO_(2) emission over critical regions.

关键词： Greenhouse gas remote sensing CO_(2)emission ODIAC GPP

Implementing the GEOSS water strategy: from observations to decisions

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International Journal of Digital Earth 2023年第1期16卷 1439-1468页

作者： Richard Lawford Sushel Unninayar George J.Huffman Wolfgang Grabs Angélica Gutiérrez Chu Ishida-Watanabe Toshio Koike Morgan State University BaltimoreUSA nasa Goddard space Flight Center GreenbeltUSA International Water Affairs Federal Institute of HydrologyKoblenz national Oceanic and Atmospheric administration Silver SpringUSA Japan Aerospace Exploration Agency Tsukuba International Centre for Water Hazard and Risk Management Tsukuba

In 2014,The GEOSS Water Strategy–From Observations to Decisions was published and steps were taken to implement the Strategy’s *** Strategy highlighted priority areas where the application of Earth observations to water research and water management decisions would have significant scientific and societal *** article reviews the implementation of the Strategy’s recommendations over the past eight *** a review of the Strategy’s assessment of the needs for water observations and their applications,it then reviews actions taken in response to the Strategy’s recommendations in its four major themes:improved data acquisition for Essential Water Variables,research and product development,interoperability,and capacity *** highlights significant achievements in the implementation of the Strategy including some motivated by factors beyond this Strategy,reviews actions taken by participating agencies and programs for each of the main themes and summarizes the remaining challenges in achieving the Strategy’s full *** article not only is an update for the Water Community regarding the GEOSS Water Strategy,but it is also an example of how other communities could develop and promulgate a set of strategic recommendations,monitor progress,and carry out assessments of their effectiveness.

关键词： Earth observations water essential water variables research interoperability capacity development

Terrestrial Analogue Research to Support Human Performance on Mars:A Review and Bibliographic Analysis

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space(Science & Technology) 2022年第1期2022卷 307-324页

作者： Andrew Terhorst Jason A.Dowling CSIRO Data 61 HobartAustralia CSIRO Australian e-Health Research Centre BrisbaneAustralia

Terrestrial analogues can provide essential scientific information and technology validation to assist future crewed missions to the Martian *** paper analyses the recent literature since 2010 in this area,highlighting key topics,authors,and research *** reviews analogue locations,missions,the scientific impact from research *** findings indicate that permanent analogue sites enable reproducible science and objective comparison between studies.A standard,open registry of analogue facilities,and associated peer-reviewed research may lead to accelerated and better targeted analogue research.

关键词： surface. analogue analogues

A Statistical Algorithm for Retrieving Background Value of Absorbing Aerosol Index Based on TROPOMI Measurements

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Advances in Atmospheric Sciences 2023年第6期40卷 1104-1116页

作者： Fuying TANG Weihe WANG Fuqi SI Haijin ZHOU Yuhan LUO Dongshang YANG Yuanyuan QIAN Key Laboratory of Environmental Optics and Technology Anhui Institute of Optics and Fine MechanicsHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites FengYun Meteorological Satellite Innovation Center(FY-MSIC)China Meteorological Administration(LRCVES/CMA)Beijing 100081China

The ultraviolet aerosol index(UVAI) is essential for monitoring the absorbing aerosols during aerosol events. UVAI depends on the absorbing aerosol concentration, the viewing geometry, and the temporal drift of radiometric sensitivity. To efficiently detect absorbing aerosols with the highest precision and to improve the accuracy of long-term UVAI estimates,the background UVAI must be examined through the UVAI retrieval. This study presents a statistical method that calculates the background value of UVAI using TROPOspheric Monitoring Instrument(TROPOMI) observation data over the Pacific Ocean under clear-sky scenes. Radiative transfer calculations were performed to simulate the dependence of UVAI on aerosol type and viewing geometry. We firstly applied the background UVAI to reducing the effects of viewing geometry and the degradation of the TROPOMI irradiance measurements on the UVAI. The temporal variability of the background UVAI under the same viewing geometry and aerosol concentration was identified. Radiative transfer calculations were performed to study the changes in background UVAI using Aerosol Optical Depth from the Moderate Resolution Imaging Spectroradiometer(MODIS) and reflectance measurements from TROPOMI as input. The trends of the temporal variations in the background UVAI agreed with the simulations. Alterations in the background UVAI expressed the reflectance variations driven by the changes in satellite state. Decreasing trends in solar irradiance at 340 and 380 nm due to instrument degradation were identified. Our findings are valuable because they can be applied to future retrievals of UVAI from the Environmental Trace Gases Monitoring Instrument(EMI) onboard the Chinese GaoFen-5 satellite.

关键词： ultraviolet aerosol index background UVAI TROPOMI reflectance degradation