A LM-2C launch vehicle was launched from the Taiyuan Satellite Launch Center on November 19, 2012, carrying HJ-1C, a technology demonstration satellite and the Fengniao satellite. The three satellites were placed to t...A LM-2C launch vehicle was launched from the Taiyuan Satellite Launch Center on November 19, 2012, carrying HJ-1C, a technology demonstration satellite and the Fengniao satellite. The three satellites were placed to the preset orbits respectively. Developed by DFH Satellite Co., Ltd., HJ-1C is a SAR Earth observation satellite for civilian use, which展开更多
The thermal infrared channel (IRS4) of HJ-1B satellite obtains view zenith angles (VZA) up to ±33°. The view angle should be taken into account when retrieving land surface temperature (LST) from IRS4 data. ...The thermal infrared channel (IRS4) of HJ-1B satellite obtains view zenith angles (VZA) up to ±33°. The view angle should be taken into account when retrieving land surface temperature (LST) from IRS4 data. This study aims at improving the mono-window algorithm for retrieving LST from IRS4 data. Based on atmospheric radiative transfer simulations,a model for correcting the VZA effects on atmospheric transmittance is proposed. In addition,a generalized model for calculating the effective mean atmospheric temperature is developed. Validation with the simulated dataset based on standard atmospheric profiles reveals that the improved mono-window algorithm for IRS4 obtains high accuracy for LST retrieval,with the mean absolute error (MAE) and root mean square error (RMSE) being 1.0 K and 1.1 K,respectively. Numerical experiment with the radiosonde profile acquired in Beijing in winter demonstrates that the improved mono-window algorithm exhibits excellent ability for LST retrieval,with MAE and RMSE being 0.6 K and 0.6 K,respectively. Further application in Qinghai Lake and comparison with the Moderate-Resolution Imaging Spectroradiometer (MODIS) LST product suggest that the improved mono-window algorithm is applicable and feasible in actual conditions.展开更多
Developed independently by China,HJ-1A/B satellites have operated well on-orbit for five years and acquired a large number of high-quality observation data.The realization of the observation data geometric precision c...Developed independently by China,HJ-1A/B satellites have operated well on-orbit for five years and acquired a large number of high-quality observation data.The realization of the observation data geometric precision correction is of great significance for macro and dynamic ecological environment monitoring.The paper analyzed the parameter characteristics of HJ-1 satellite and geometric features of HJ-1 satellite level 2 data(systematic geo- corrected data).Based on this,the overall HJ- 1 multi- sensor geometric correction flow and charge-coupled device(CCD) automatic geometric precision correction method were designed.Actual operating data showed that the method could achieve good result for automatic geometric precision correction of HJ-1 satellite data,automatic HJ-1 CCD image geometric precision correction accuracy could be achieved within two pixels and automatic matching accuracy between the images of same satellite could be obtained less than one pixel.展开更多
A massive iceberg, named A-68 by National Ice Center （NIC） officially, calved away from the Larsen C Ice Shelf in Antarctica on luly 12, 2017. The iceberg A-68 is about 5 800 km2, weighs more than a trillion tons an...A massive iceberg, named A-68 by National Ice Center （NIC） officially, calved away from the Larsen C Ice Shelf in Antarctica on luly 12, 2017. The iceberg A-68 is about 5 800 km2, weighs more than a trillion tons and it is one of the biggest ever recorded icebergs. Chinese satellites Gaofen-1 （GF-1） and Gaofen-3 （GF-3） data was used to monitoring the propagation of the rift and the iceberg by National Satellite Ocean Application Service （NSOAS）.展开更多
In 2018,China successfully launched three new Haiyang(which means ocean in Chinese,referred to as HY)satellites which are an ocean color observation satellite HY-1C(operational),an ocean dynamics environment satellite...In 2018,China successfully launched three new Haiyang(which means ocean in Chinese,referred to as HY)satellites which are an ocean color observation satellite HY-1C(operational),an ocean dynamics environment satellite HY-2B(operational)and the China-France ocean satellite CFOSAT(experimental).In 2019,all the three satellites had finished their commissioning phases and were declared operational.HY-2A satellite continues to operate in-orbit,and its operational status is basically normal.So in 2020,China has 4 Haiyang satellites in-orbit,China’s ocean satellites enter into a new operational application phase.The operation of the ground application system of Chinese ocean satellites is stable.In 2019,Beijing,Hainan,Mudanjiang,and Hangzhou ocean satellite ground stations had received the data of HY-1C,HY-2A,HY-2B,and CFOSAT 5012 orbits and 26.46 TB data had been distributed to both domestic and international users.Chinese ocean satellite data has played an important role in marine disaster prevention and mitigation,development and management of marine resources,maintenance of marine rights and interests,marine environment protection,scientific researches,and blue economy development.展开更多
Plague,caused by the gram-negative bacterium Yersinia pestis,is a serious and rapidly progressing illness in humans that can be fatal if not treated effectively.The Qinghai-Tibet Plateau is the largest area of natural...Plague,caused by the gram-negative bacterium Yersinia pestis,is a serious and rapidly progressing illness in humans that can be fatal if not treated effectively.The Qinghai-Tibet Plateau is the largest area of natural Himalayan marmot(Marmota himalayana) plague foci in China and covers more than 630000 km2.Akesai County in Gansu Province is a part of this natural focus of plague and was chosen as a study area.Our study used an ecological niche modeling(ENM) approach to predict the potential distribution of the Himalayan marmot.Environment and Disaster Monitor Satellite(HJ-1) data was used to investigate environment factors that affect plague host animal activity.Host animal point data from active surveillance was combined with environmental variables from the HJ-1 satellite and other databases,and the models of the potential distribution of Himalayan marmot were produced with the Genetic Algorithm for Rule-Set Production(GARP).The probability of marmot presence was divided into 0-5%,5%-20%,20%-40%,40%-80%,and 80%-100% subgroups.Areas with 80%-100% probability exhibited the greatest potential for the presence of Himalayan marmot.According to the predicted potential distribution of Himalayan marmot in the study area,active surveillance of plague hosts and plague control and prevention could be more efficient.展开更多
Photosynthetically active radiation(PAR) is essential for plant photosynthesis and carbon cycle,and is also important for meteorological and environmental monitoring.To advance China's disaster and environmental m...Photosynthetically active radiation(PAR) is essential for plant photosynthesis and carbon cycle,and is also important for meteorological and environmental monitoring.To advance China's disaster and environmental monitoring capabilities,the HJ-1A/B satellites have been placed in Earth orbit.One of their environmental monitoring objectives is the study of PAR.We simulated direct solar,scattered and environment radiation between 400 and 700 nm under different atmospheric parameters(solar zenith angle,atmospheric water vapor,atmospheric ozone,aerosol optical thickness,surface elevation and surface albedo),and then established a look-up table between these input parameters and PAR.Based on the look-up table,we used HJ-1A/B aerosol and surface albedo outputs to derive the corresponding PAR.Validation of inversed instantaneous and observed PAR values using HJ-1 Heihe experimental data had a root mean square error of 25.2 W m-2,with a relative error of 5.9%.The root mean square error for accumulated daily PAR and observed values was 0.49 MJ m-2,with a relative error of 3.5%.Our approach improved significantly the computational efficiency,compared with using directly radiation transfer equations.We also studied the sensitivity of various input parameters to photosynthetically active radiation,and found that solar zenith angle and atmospheric aerosols were sensitive PAR parameters.Surface albedo had some effect on PAR,but water vapor and ozone had minimal impact on PAR.展开更多
Aerosol optical depth （AOD） is a common indicator applied in monitoring aerosols in the atmosphere. The hilly landscape and rapid economic growth of the megacity Chongqing have facilitated increased aerosol concentr...Aerosol optical depth （AOD） is a common indicator applied in monitoring aerosols in the atmosphere. The hilly landscape and rapid economic growth of the megacity Chongqing have facilitated increased aerosol concentration, and it is meaningful to accurately retrieve AOD over Chongqing. The HJ-1A/B satellite of China carries a sensor/camera called the Charge Coupled Device （CCD）, the spatial resolution of which meets the requirement for re- trieving high resolution AOD. In this paper, analysis of the AOD retrievals from different methods using the H J-1 satellite data revealed the most suitable algorithm. Through comparison with the AOD product of Moderate Resolu- tion Imaging Spectroradiometer （MODIS）, the AOD retrieval results using enhanced vegetation index （EVI） to estim- ate dark pixels showed the highest correlation. The continental aerosol model was used to build a lookup table that was able to facilitate a good AOD retrieval for both city and rural areas. Finally, the algorithm that combined dark pixels, buffer areas, and the deep blue algorithm was found to be most suitable for AOD retrieval. The AOD retrieval results based on the HJ-1 data were consistent with MODIS products, and our algorithm yields reasonable results in most cases. The results were also compared with ground-based PMl0 measurements synchronized with the overpass time of the HJ-1 satellite, and high correlation was found. The findings are relevant to other Chinese satellite data used for retrieving AOD on the same channels.展开更多
The Chinese Government attaches great importance to applications of satellite remote sensing in environmental monitoring.On 6 September 2008,the first two satellites of the Environment and Disaster Monitoring and Pred...The Chinese Government attaches great importance to applications of satellite remote sensing in environmental monitoring.On 6 September 2008,the first two satellites of the Environment and Disaster Monitoring and Prediction Satellite Constellation(HJ),HJ-1A and HJ-1B,were successfully launched,which started a new era of satellite applications for environmental monitoring in China.An introduction to the satellite,instrument,and ground systems of HJ-1A and HJ-1B is presented in this article,and an analysis of their technical performance and characteristics is also given.Focusing on the operational needs of environmental monitoring in China,the general design,functional construction,and operational mode of the application system of HJ-1A and HJ-1B are detailed,and the operations and applications of the two satellites are also discussed.展开更多
文摘A LM-2C launch vehicle was launched from the Taiyuan Satellite Launch Center on November 19, 2012, carrying HJ-1C, a technology demonstration satellite and the Fengniao satellite. The three satellites were placed to the preset orbits respectively. Developed by DFH Satellite Co., Ltd., HJ-1C is a SAR Earth observation satellite for civilian use, which
基金Under the auspices of Opening Funding of State Key Laboratory for Remote Sensing ScienceNational High-tech Research and Development Program (863 Program) (No. 2007AA120205, 2007AA120306)
文摘The thermal infrared channel (IRS4) of HJ-1B satellite obtains view zenith angles (VZA) up to ±33°. The view angle should be taken into account when retrieving land surface temperature (LST) from IRS4 data. This study aims at improving the mono-window algorithm for retrieving LST from IRS4 data. Based on atmospheric radiative transfer simulations,a model for correcting the VZA effects on atmospheric transmittance is proposed. In addition,a generalized model for calculating the effective mean atmospheric temperature is developed. Validation with the simulated dataset based on standard atmospheric profiles reveals that the improved mono-window algorithm for IRS4 obtains high accuracy for LST retrieval,with the mean absolute error (MAE) and root mean square error (RMSE) being 1.0 K and 1.1 K,respectively. Numerical experiment with the radiosonde profile acquired in Beijing in winter demonstrates that the improved mono-window algorithm exhibits excellent ability for LST retrieval,with MAE and RMSE being 0.6 K and 0.6 K,respectively. Further application in Qinghai Lake and comparison with the Moderate-Resolution Imaging Spectroradiometer (MODIS) LST product suggest that the improved mono-window algorithm is applicable and feasible in actual conditions.
文摘Developed independently by China,HJ-1A/B satellites have operated well on-orbit for five years and acquired a large number of high-quality observation data.The realization of the observation data geometric precision correction is of great significance for macro and dynamic ecological environment monitoring.The paper analyzed the parameter characteristics of HJ-1 satellite and geometric features of HJ-1 satellite level 2 data(systematic geo- corrected data).Based on this,the overall HJ- 1 multi- sensor geometric correction flow and charge-coupled device(CCD) automatic geometric precision correction method were designed.Actual operating data showed that the method could achieve good result for automatic geometric precision correction of HJ-1 satellite data,automatic HJ-1 CCD image geometric precision correction accuracy could be achieved within two pixels and automatic matching accuracy between the images of same satellite could be obtained less than one pixel.
基金The National Key Research and Development Program of China under contract Nos 2016YFC1402704 and2016YFC1401007the International Science and Technology Cooperation Project of China under contract No.2011DFA22260
文摘A massive iceberg, named A-68 by National Ice Center （NIC） officially, calved away from the Larsen C Ice Shelf in Antarctica on luly 12, 2017. The iceberg A-68 is about 5 800 km2, weighs more than a trillion tons and it is one of the biggest ever recorded icebergs. Chinese satellites Gaofen-1 （GF-1） and Gaofen-3 （GF-3） data was used to monitoring the propagation of the rift and the iceberg by National Satellite Ocean Application Service （NSOAS）.
文摘In 2018,China successfully launched three new Haiyang(which means ocean in Chinese,referred to as HY)satellites which are an ocean color observation satellite HY-1C(operational),an ocean dynamics environment satellite HY-2B(operational)and the China-France ocean satellite CFOSAT(experimental).In 2019,all the three satellites had finished their commissioning phases and were declared operational.HY-2A satellite continues to operate in-orbit,and its operational status is basically normal.So in 2020,China has 4 Haiyang satellites in-orbit,China’s ocean satellites enter into a new operational application phase.The operation of the ground application system of Chinese ocean satellites is stable.In 2019,Beijing,Hainan,Mudanjiang,and Hangzhou ocean satellite ground stations had received the data of HY-1C,HY-2A,HY-2B,and CFOSAT 5012 orbits and 26.46 TB data had been distributed to both domestic and international users.Chinese ocean satellite data has played an important role in marine disaster prevention and mitigation,development and management of marine resources,maintenance of marine rights and interests,marine environment protection,scientific researches,and blue economy development.
基金supported by the Special Grant for Prevention and Treatment of Infectious Diseases (Grant No.2008ZX10004-012)National Natural Science Foundation of China (Grant No.40871173)
文摘Plague,caused by the gram-negative bacterium Yersinia pestis,is a serious and rapidly progressing illness in humans that can be fatal if not treated effectively.The Qinghai-Tibet Plateau is the largest area of natural Himalayan marmot(Marmota himalayana) plague foci in China and covers more than 630000 km2.Akesai County in Gansu Province is a part of this natural focus of plague and was chosen as a study area.Our study used an ecological niche modeling(ENM) approach to predict the potential distribution of the Himalayan marmot.Environment and Disaster Monitor Satellite(HJ-1) data was used to investigate environment factors that affect plague host animal activity.Host animal point data from active surveillance was combined with environmental variables from the HJ-1 satellite and other databases,and the models of the potential distribution of Himalayan marmot were produced with the Genetic Algorithm for Rule-Set Production(GARP).The probability of marmot presence was divided into 0-5%,5%-20%,20%-40%,40%-80%,and 80%-100% subgroups.Areas with 80%-100% probability exhibited the greatest potential for the presence of Himalayan marmot.According to the predicted potential distribution of Himalayan marmot in the study area,active surveillance of plague hosts and plague control and prevention could be more efficient.
基金supported by National High Technology Research and Development Program of China (Grant No.2009AA12210)National Key Technology R&D Program (Grant No.2008BAC34B03)the National Natural Science Foundation of China (Grant Nos.40730525,40971204)
文摘Photosynthetically active radiation(PAR) is essential for plant photosynthesis and carbon cycle,and is also important for meteorological and environmental monitoring.To advance China's disaster and environmental monitoring capabilities,the HJ-1A/B satellites have been placed in Earth orbit.One of their environmental monitoring objectives is the study of PAR.We simulated direct solar,scattered and environment radiation between 400 and 700 nm under different atmospheric parameters(solar zenith angle,atmospheric water vapor,atmospheric ozone,aerosol optical thickness,surface elevation and surface albedo),and then established a look-up table between these input parameters and PAR.Based on the look-up table,we used HJ-1A/B aerosol and surface albedo outputs to derive the corresponding PAR.Validation of inversed instantaneous and observed PAR values using HJ-1 Heihe experimental data had a root mean square error of 25.2 W m-2,with a relative error of 5.9%.The root mean square error for accumulated daily PAR and observed values was 0.49 MJ m-2,with a relative error of 3.5%.Our approach improved significantly the computational efficiency,compared with using directly radiation transfer equations.We also studied the sensitivity of various input parameters to photosynthetically active radiation,and found that solar zenith angle and atmospheric aerosols were sensitive PAR parameters.Surface albedo had some effect on PAR,but water vapor and ozone had minimal impact on PAR.
基金Supported by the National Natural Science Foundation of China(41631180 and 41471305)Sichuan Youth Science Fund(2015JQ0037)+2 种基金Chongqing Meteorological Bureau Open Fund(kfjj-201402)China Meteorological Administration Special Fund for Forecasting(CMAHX20160406)Sichuan Province Department of Education Innovation Team Fund(16TD0024)
文摘Aerosol optical depth （AOD） is a common indicator applied in monitoring aerosols in the atmosphere. The hilly landscape and rapid economic growth of the megacity Chongqing have facilitated increased aerosol concentration, and it is meaningful to accurately retrieve AOD over Chongqing. The HJ-1A/B satellite of China carries a sensor/camera called the Charge Coupled Device （CCD）, the spatial resolution of which meets the requirement for re- trieving high resolution AOD. In this paper, analysis of the AOD retrievals from different methods using the H J-1 satellite data revealed the most suitable algorithm. Through comparison with the AOD product of Moderate Resolu- tion Imaging Spectroradiometer （MODIS）, the AOD retrieval results using enhanced vegetation index （EVI） to estim- ate dark pixels showed the highest correlation. The continental aerosol model was used to build a lookup table that was able to facilitate a good AOD retrieval for both city and rural areas. Finally, the algorithm that combined dark pixels, buffer areas, and the deep blue algorithm was found to be most suitable for AOD retrieval. The AOD retrieval results based on the HJ-1 data were consistent with MODIS products, and our algorithm yields reasonable results in most cases. The results were also compared with ground-based PMl0 measurements synchronized with the overpass time of the HJ-1 satellite, and high correlation was found. The findings are relevant to other Chinese satellite data used for retrieving AOD on the same channels.
文摘The Chinese Government attaches great importance to applications of satellite remote sensing in environmental monitoring.On 6 September 2008,the first two satellites of the Environment and Disaster Monitoring and Prediction Satellite Constellation(HJ),HJ-1A and HJ-1B,were successfully launched,which started a new era of satellite applications for environmental monitoring in China.An introduction to the satellite,instrument,and ground systems of HJ-1A and HJ-1B is presented in this article,and an analysis of their technical performance and characteristics is also given.Focusing on the operational needs of environmental monitoring in China,the general design,functional construction,and operational mode of the application system of HJ-1A and HJ-1B are detailed,and the operations and applications of the two satellites are also discussed.
