Fengyun-3 E(FY-3E),the world’s first early-morning-orbit meteorological satellite for civil use,was launched successfully at the Jiuquan Satellite Launch Center on 5 July 2021.The FY-3E satellite will fill the vacanc...Fengyun-3 E(FY-3E),the world’s first early-morning-orbit meteorological satellite for civil use,was launched successfully at the Jiuquan Satellite Launch Center on 5 July 2021.The FY-3E satellite will fill the vacancy of the global early-morning-orbit satellite observation,working together with the FY-3C and FY-3D satellites to achieve the data coverage of early morning,morning,and afternoon orbits.The combination of these three satellites will provide global data coverage for numerical weather prediction(NWP)at 6-hour intervals,effectively improving the accuracy and time efficiency of global NWP,which is of great significance to perfect the global earth observing system.In this article,the background and meteorological requirements for the early-morning-orbit satellite are reviewed,and the specifications of the FY-3E satellite,as well as the characteristics of the onboard instrumentation for earth observations,are also introduced.In addition,the ground segment and the retrieved geophysical products are also presented.It is believed that the NWP communities will significantly benefit from an optimal temporal distribution of observations provided by the early morning,mid-morning,and afternoon satellite missions.Further benefits are expected in numerous applications such as the monitoring of severe weather/climate events,the development of improved sampling designs of the diurnal cycle for accurate climate data records,more efficient monitoring of air quality by thermal infrared remote sensing,and the quasicontinuous monitoring of the sun for space weather and climate.展开更多
On 5 July 2021, the China FY-3E satellite was successfully launched, equipped with instruments to measure ultralow frequency waves(ULF) and charged particle populations deep within the magnetosphere. In this study, we...On 5 July 2021, the China FY-3E satellite was successfully launched, equipped with instruments to measure ultralow frequency waves(ULF) and charged particle populations deep within the magnetosphere. In this study, we report two ULF wave events observed by the FY-3E satellite, which are closely associated with magnetospheric substorms, in conjunction with observations from the Swarm satellite. We noticed a significant similarity between the ULF waves recorded by FY-3E and Swarm, indicating that these satellites captured the same wave events. The presence of a 180° phase shift across L shells and an oscillating field aligned Poynting flux suggest that the observed ULF waves exhibit characteristics of field line resonance(FLR).This work also characterizes essential differences in the behavior of ULF pulsations affected by the South Atlantic anomaly(SAA) in comparison to a conjugate region outside. Wave packets in the SAA region exhibit higher amplitudes than the pulsations in the northern hemisphere. This difference is likely influenced by the north-south asymmetry of the geomagnetic field and ionospheric conductivities, which, in turn, control the standing wave structure along the field line.展开更多
With the launch of the first civilian early-morning orbit satellite Fengyun-3E(FY-3E),higher demands are placed on the accuracy of radiative transfer simulations for hyperspectral infrared data.Therefore,several key i...With the launch of the first civilian early-morning orbit satellite Fengyun-3E(FY-3E),higher demands are placed on the accuracy of radiative transfer simulations for hyperspectral infrared data.Therefore,several key issues are investigated in the paper.First,the accuracy of the fast atmospheric transmittance model implemented in the Advanced Research and Modeling System(ARMS)has been evaluated with both the line-by-line radiative transfer model(LBLRTM)and the actual satellite observations.The results indicate that the biases are generally less than 0.25 K when compared to the LBLRTM,while below 1.0 K for the majority of the channels when compared to the observations.However,during both comparisons,significant biases are observed in certain channels.The accuracy of Hyperspectral Infrared Atmospheric Sounder-II(HIRAS-II)onboard FY-3E is comparable to,and even superior to that of the Cross-track Infrared Sounder(CrIS)onboard NOAA-20.Furthermore,apodization is a crucial step in the processing of hyperspectral data in that the apodization function is utilized as the instrument channel spectral response function to produce the satellite channel-averaged transmittance.To further explore the difference between the apodized and unapodized simulations,Sinc function is adopted in the fast transmittance model.It is found that the use of Sinc function can make the simulations fit the original satellite observations better.When simulating with apodized observations,the use of Sinc function exhibits larger deviations compared to the Hamming function.Moreover,a correction module is applied to minimize the impact of Non-Local Thermodynamic Equilibrium(NLTE)in the shortwave infrared band.It is verified that the implementation of the NLTE correction model leads to a significant reduction in the bias between the simulation and observation for this band.展开更多
Sea ice,a significant component in polar regions,plays a crucial role in climate change through its varying conditions.In Global Navigation Satellite System-Reflectometry(GNSS-R)studies,the observed surface reflectiv...Sea ice,a significant component in polar regions,plays a crucial role in climate change through its varying conditions.In Global Navigation Satellite System-Reflectometry(GNSS-R)studies,the observed surface reflectivityΓserves as a tool to examine the physical characteristics of sea ice covers.This facilitates the large-scale estimation of first-year ice thickness using a two-layer sea ice-seawater medium model.However,it is important to note that when Sea Ice Thickness(SIT)becomes thicker,the accuracy of SIT retrieval via this two-layer model begins to decline.In this paper,we present a novel application of a spaceborne GNSS-R technique to retrieve SIT based on a three-layer model using the data from Fengyun-3E(FY-3E).Soil Moisture Ocean Salinity(SMOS)data are treated as the reference.The performance of the proposed three-layer model is evaluated against a previously established two-layer model for SIT retrieval.The analysis used the sea ice data from 2022 and 2023 with SITs less than 1.1 m.By comparing the retrieved SITs against reference values,the three-layer model achieved a Root Mean Square Error(RMSE)of 0.149 m and Correlation Coefficient(r)of 0.830,while the two-layer model reported the RMSE of 0.162 m and r value of 0.789.A scheme incorporating both models yielded superior results than either individual model,with the RMSE of 0.137 m and r reaching up to 0.852.This study is the first application of FY-3E for GNSS-R SIT retrieval,combining the advantages of a two-layer model and a three-layer model and extending the precision of GNSS-R retrieval for SIT to within 1.1 m.This provides a good reference for the future studies on GNSS-R SIT retrieval.展开更多
This study proposes a novel AC vector magnetometer developed using a low-resource magneto-impedance sensor for China’s Feng-Yun meteorological satellite(FY-3E).It was calibrated and characterized to determine its per...This study proposes a novel AC vector magnetometer developed using a low-resource magneto-impedance sensor for China’s Feng-Yun meteorological satellite(FY-3E).It was calibrated and characterized to determine its performance parameters.The total weight of the AC vector magnetometer is 51 g(the aluminum box excluded),while the total power consumption is 310 m W.The proposed AC vector magnetometer can detect magnetic field variations in the range of±1000 nT and noise power spectral density of≤50 pT/Hz^(1/2)@1 Hz.Furthermore,the proposed device has a maximum nonlinearity of≤0.71‰over the entire range and a nonorthogonality error of 3.07 nT or 0.15%(root mean square).The total dose hardness of the sensor is≥30 krad(Si).Furthermore,we propose the first survey results of a magnetometer equipped aboard a Chinese FY-3E satellite in a Sunsynchronous orbit.The data revealed that the AC vector magnetometer can detect transient physical signals such as quasistatic field-aligned currents(~50 nT)and waves at the auroral latitudes.These features render the proposed AC vector magnetometer suitable for space-based applications,particularly those involving the study of geomagnetic activity.展开更多
基金funded by the FY3-03 project and the National Key Technology Research and Development Program of China(Grant Nos.2018YFB0504900 and 2018YFB0504905)。
文摘Fengyun-3 E(FY-3E),the world’s first early-morning-orbit meteorological satellite for civil use,was launched successfully at the Jiuquan Satellite Launch Center on 5 July 2021.The FY-3E satellite will fill the vacancy of the global early-morning-orbit satellite observation,working together with the FY-3C and FY-3D satellites to achieve the data coverage of early morning,morning,and afternoon orbits.The combination of these three satellites will provide global data coverage for numerical weather prediction(NWP)at 6-hour intervals,effectively improving the accuracy and time efficiency of global NWP,which is of great significance to perfect the global earth observing system.In this article,the background and meteorological requirements for the early-morning-orbit satellite are reviewed,and the specifications of the FY-3E satellite,as well as the characteristics of the onboard instrumentation for earth observations,are also introduced.In addition,the ground segment and the retrieved geophysical products are also presented.It is believed that the NWP communities will significantly benefit from an optimal temporal distribution of observations provided by the early morning,mid-morning,and afternoon satellite missions.Further benefits are expected in numerous applications such as the monitoring of severe weather/climate events,the development of improved sampling designs of the diurnal cycle for accurate climate data records,more efficient monitoring of air quality by thermal infrared remote sensing,and the quasicontinuous monitoring of the sun for space weather and climate.
基金supported by the National Natural Science Foundation of China (Grant Nos. 42204167, 42174184 and 41974191)the National Key Research and Development Program of China (2021YFA0718600)+1 种基金the Informatization Plan of Chinese Academy of Sciences (Grant No. CAS-WX2022SF-0103)financial support from the Canadian Space Agency。
文摘On 5 July 2021, the China FY-3E satellite was successfully launched, equipped with instruments to measure ultralow frequency waves(ULF) and charged particle populations deep within the magnetosphere. In this study, we report two ULF wave events observed by the FY-3E satellite, which are closely associated with magnetospheric substorms, in conjunction with observations from the Swarm satellite. We noticed a significant similarity between the ULF waves recorded by FY-3E and Swarm, indicating that these satellites captured the same wave events. The presence of a 180° phase shift across L shells and an oscillating field aligned Poynting flux suggest that the observed ULF waves exhibit characteristics of field line resonance(FLR).This work also characterizes essential differences in the behavior of ULF pulsations affected by the South Atlantic anomaly(SAA) in comparison to a conjugate region outside. Wave packets in the SAA region exhibit higher amplitudes than the pulsations in the northern hemisphere. This difference is likely influenced by the north-south asymmetry of the geomagnetic field and ionospheric conductivities, which, in turn, control the standing wave structure along the field line.
基金Supported by the Startup Project of Donghai Laboratory(DH-2023QD0002)National Key Research and Development Program of China(2021YFB3900400)Hunan Provincial Natural Science Foundation of China(2021JC0009)。
文摘With the launch of the first civilian early-morning orbit satellite Fengyun-3E(FY-3E),higher demands are placed on the accuracy of radiative transfer simulations for hyperspectral infrared data.Therefore,several key issues are investigated in the paper.First,the accuracy of the fast atmospheric transmittance model implemented in the Advanced Research and Modeling System(ARMS)has been evaluated with both the line-by-line radiative transfer model(LBLRTM)and the actual satellite observations.The results indicate that the biases are generally less than 0.25 K when compared to the LBLRTM,while below 1.0 K for the majority of the channels when compared to the observations.However,during both comparisons,significant biases are observed in certain channels.The accuracy of Hyperspectral Infrared Atmospheric Sounder-II(HIRAS-II)onboard FY-3E is comparable to,and even superior to that of the Cross-track Infrared Sounder(CrIS)onboard NOAA-20.Furthermore,apodization is a crucial step in the processing of hyperspectral data in that the apodization function is utilized as the instrument channel spectral response function to produce the satellite channel-averaged transmittance.To further explore the difference between the apodized and unapodized simulations,Sinc function is adopted in the fast transmittance model.It is found that the use of Sinc function can make the simulations fit the original satellite observations better.When simulating with apodized observations,the use of Sinc function exhibits larger deviations compared to the Hamming function.Moreover,a correction module is applied to minimize the impact of Non-Local Thermodynamic Equilibrium(NLTE)in the shortwave infrared band.It is verified that the implementation of the NLTE correction model leads to a significant reduction in the bias between the simulation and observation for this band.
基金funded by the National Natural Science Foundation of China under Grant 42001362.
文摘Sea ice,a significant component in polar regions,plays a crucial role in climate change through its varying conditions.In Global Navigation Satellite System-Reflectometry(GNSS-R)studies,the observed surface reflectivityΓserves as a tool to examine the physical characteristics of sea ice covers.This facilitates the large-scale estimation of first-year ice thickness using a two-layer sea ice-seawater medium model.However,it is important to note that when Sea Ice Thickness(SIT)becomes thicker,the accuracy of SIT retrieval via this two-layer model begins to decline.In this paper,we present a novel application of a spaceborne GNSS-R technique to retrieve SIT based on a three-layer model using the data from Fengyun-3E(FY-3E).Soil Moisture Ocean Salinity(SMOS)data are treated as the reference.The performance of the proposed three-layer model is evaluated against a previously established two-layer model for SIT retrieval.The analysis used the sea ice data from 2022 and 2023 with SITs less than 1.1 m.By comparing the retrieved SITs against reference values,the three-layer model achieved a Root Mean Square Error(RMSE)of 0.149 m and Correlation Coefficient(r)of 0.830,while the two-layer model reported the RMSE of 0.162 m and r value of 0.789.A scheme incorporating both models yielded superior results than either individual model,with the RMSE of 0.137 m and r reaching up to 0.852.This study is the first application of FY-3E for GNSS-R SIT retrieval,combining the advantages of a two-layer model and a three-layer model and extending the precision of GNSS-R retrieval for SIT to within 1.1 m.This provides a good reference for the future studies on GNSS-R SIT retrieval.
基金supported by the National Natural Science Foundation of China (Grant No.42074223)。
文摘This study proposes a novel AC vector magnetometer developed using a low-resource magneto-impedance sensor for China’s Feng-Yun meteorological satellite(FY-3E).It was calibrated and characterized to determine its performance parameters.The total weight of the AC vector magnetometer is 51 g(the aluminum box excluded),while the total power consumption is 310 m W.The proposed AC vector magnetometer can detect magnetic field variations in the range of±1000 nT and noise power spectral density of≤50 pT/Hz^(1/2)@1 Hz.Furthermore,the proposed device has a maximum nonlinearity of≤0.71‰over the entire range and a nonorthogonality error of 3.07 nT or 0.15%(root mean square).The total dose hardness of the sensor is≥30 krad(Si).Furthermore,we propose the first survey results of a magnetometer equipped aboard a Chinese FY-3E satellite in a Sunsynchronous orbit.The data revealed that the AC vector magnetometer can detect transient physical signals such as quasistatic field-aligned currents(~50 nT)and waves at the auroral latitudes.These features render the proposed AC vector magnetometer suitable for space-based applications,particularly those involving the study of geomagnetic activity.
