Sea surface salinity(SSS)is an essential variable of ocean dynamics and climate research.The Soil Moisture and Ocean Salinity(SMOS),Aquarius,and Soil Moisture Active Passive(SMAP)satellite missions all provide SSS mea...Sea surface salinity(SSS)is an essential variable of ocean dynamics and climate research.The Soil Moisture and Ocean Salinity(SMOS),Aquarius,and Soil Moisture Active Passive(SMAP)satellite missions all provide SSS measurements.The European Space Agency(ESA)Climate Change Initiative Sea Surface Salinity(CCI-SSS)project merged these three satellite SSS data to produce CCI L4SSS products.We validated the accuracy of the four satellite products(CCI,SMOS,Aquarius,and SMAP)using in-situ gridded data and Argo floats in the South China Sea(SCS).Compared with in-situ gridded data,it shows that the CCI achieved the best performance(RMSD:0.365)on monthly time scales.The RMSD of SMOS,Aquarius,and SMAP(SMOS:0.389;Aquarius:0.409;SMAP:0.391)are close,and the SMOS takes a slight advantage in contrast with Aquarius and SMAP.Large discrepancies can be found near the coastline and in the shelf seas.Meanwhile,CCI with lower RMSD(0.295)perform better than single satellite data(SMOS:0.517;SMAP:0.297)on weekly time scales compared with Argo floats.Overall,the merged CCI have the smallest RMSD among the four satellite products in the SCS on both weekly time scales and monthly time scales,which illustrates the improved accuracy of merged CCI compared with the individual satellite data.展开更多
Utilizing more than 30 years of satellite-microwave sensor derived snow water equivalent data on the high-latitudes of the northern hemisphere we investigate regional trends and variations relative to elevation. On th...Utilizing more than 30 years of satellite-microwave sensor derived snow water equivalent data on the high-latitudes of the northern hemisphere we investigate regional trends and variations relative to elevation. On the low-elevation tundra regions encircling the Arctic we find high statistically significant trends of snow water equivalent. Across the high Arctic Siberia and Far East Russia through North America and northern Greenland we find increasing trends of snow water equivalent with local region variations in strength. Yet across the high Arctic of western Russia through Norway we find decreasing trends of snow water equivalent of varying strength. Power density spectra identify significant power at quasi-biennial and associated lunar nodal cycles. These cycles of the upper atmosphere circulation, ENSO and ocean circulation perturbations from tides forms the causative linkage between increasing snow water equivalent on low-elevation tundra landscapes and decreasing coastal sea ice cover as part of the Arctic system energy and mass cycles.展开更多
Using GNSS-R technology for remote sensing of surface parameters has become a new trend in the field of remote sensing.With the rapid development of GNSS-R technology,GNSS-R simulation has become one of the new hot sp...Using GNSS-R technology for remote sensing of surface parameters has become a new trend in the field of remote sensing.With the rapid development of GNSS-R technology,GNSS-R simulation has become one of the new hot spots.Now the researches of the GNSS-R simulation are all the simulations that consider a single star or a single frequency point,and in actual applications,the signal captured by the receiver is often the reflected signals of multiple stars.In view of this situation,from the perspective of multi-satellite simulation,this paper gives the model of GNSS-R multi-satellite ocean simulation on the basis of analyzing the remote sensing principle,reflection signal model and simulation principle of GNSS-R technology.Based on the GNSS-R multi-satellite ocean simulation model and the fast parallel computing capability of GPU,the GNSS-R multi-satellite ocean simulator was designed.Finally,the direct and reflected signals generated by the GNSS-R multi-satellite simulator were tested and verified.The results show that the positioning result of the direct signal meets the positioning accuracy requirements;The delay-related power results obtained from the simulated two-satellite reflected signals processing are in good agreement with the theoretical model,and the correlation coefficients are all above 0.99;The generated signals are used for GNSS-R height measurement technology,the height measurement error is about 1.4~1.8 m,which is in line with the accuracy of the C/A code ranging receiver;And the parallel operation of the GPU for multi-satellite simulation calculation is 800—900 times higher than the traditional CPU calculation.It proves that the proposed model and the designed simulator are feasible and accurate.展开更多
A scheme is proposed to elevate the limitation of the ground application system of mono-satellite-sensor under the requirement of remote sensing satellite ground application system.In the resource-sharing, for instanc...A scheme is proposed to elevate the limitation of the ground application system of mono-satellite-sensor under the requirement of remote sensing satellite ground application system.In the resource-sharing, for instance caculating resource, a simple phototype of caculating-resource is proposed through analyzing resource assignment, application assignment, body structure, and so on. In order to improve the ability of assignment, realize the favorable utility, management,and maintenance, the phototype is improved by using datagrid calculation according to the requirement and character of actual application. The phototype can be taken as the foundation of calculation frame of remote sensing ground application system of multi-satellite and multi-sensor.展开更多
针对光伏发电、水电及风电联合运行时电量外送因输电断面限额导致的弃水问题,分析了线路输电断面限额的机理,建立了考虑输电断面极限传输容量(Total Transfer Capability,TTC)以外送电量最大为目标,基于采用两时段滑动寻优算法(Progress...针对光伏发电、水电及风电联合运行时电量外送因输电断面限额导致的弃水问题,分析了线路输电断面限额的机理,建立了考虑输电断面极限传输容量(Total Transfer Capability,TTC)以外送电量最大为目标,基于采用两时段滑动寻优算法(Progressive Optimization Algorithm,POA)的光伏发电、水电及风电联合运行长期优化调度模型,利用水电站的库容储能进行调峰,提高输电线路的使用率。仿真算例证明,所提模型具有较高可行性和有效性。展开更多
基金Supported by the National Natural Science Foundation of China(No.42075149)。
文摘Sea surface salinity(SSS)is an essential variable of ocean dynamics and climate research.The Soil Moisture and Ocean Salinity(SMOS),Aquarius,and Soil Moisture Active Passive(SMAP)satellite missions all provide SSS measurements.The European Space Agency(ESA)Climate Change Initiative Sea Surface Salinity(CCI-SSS)project merged these three satellite SSS data to produce CCI L4SSS products.We validated the accuracy of the four satellite products(CCI,SMOS,Aquarius,and SMAP)using in-situ gridded data and Argo floats in the South China Sea(SCS).Compared with in-situ gridded data,it shows that the CCI achieved the best performance(RMSD:0.365)on monthly time scales.The RMSD of SMOS,Aquarius,and SMAP(SMOS:0.389;Aquarius:0.409;SMAP:0.391)are close,and the SMOS takes a slight advantage in contrast with Aquarius and SMAP.Large discrepancies can be found near the coastline and in the shelf seas.Meanwhile,CCI with lower RMSD(0.295)perform better than single satellite data(SMOS:0.517;SMAP:0.297)on weekly time scales compared with Argo floats.Overall,the merged CCI have the smallest RMSD among the four satellite products in the SCS on both weekly time scales and monthly time scales,which illustrates the improved accuracy of merged CCI compared with the individual satellite data.
文摘Utilizing more than 30 years of satellite-microwave sensor derived snow water equivalent data on the high-latitudes of the northern hemisphere we investigate regional trends and variations relative to elevation. On the low-elevation tundra regions encircling the Arctic we find high statistically significant trends of snow water equivalent. Across the high Arctic Siberia and Far East Russia through North America and northern Greenland we find increasing trends of snow water equivalent with local region variations in strength. Yet across the high Arctic of western Russia through Norway we find decreasing trends of snow water equivalent of varying strength. Power density spectra identify significant power at quasi-biennial and associated lunar nodal cycles. These cycles of the upper atmosphere circulation, ENSO and ocean circulation perturbations from tides forms the causative linkage between increasing snow water equivalent on low-elevation tundra landscapes and decreasing coastal sea ice cover as part of the Arctic system energy and mass cycles.
基金National Natural Science Foundation of China(No.41774028)。
文摘Using GNSS-R technology for remote sensing of surface parameters has become a new trend in the field of remote sensing.With the rapid development of GNSS-R technology,GNSS-R simulation has become one of the new hot spots.Now the researches of the GNSS-R simulation are all the simulations that consider a single star or a single frequency point,and in actual applications,the signal captured by the receiver is often the reflected signals of multiple stars.In view of this situation,from the perspective of multi-satellite simulation,this paper gives the model of GNSS-R multi-satellite ocean simulation on the basis of analyzing the remote sensing principle,reflection signal model and simulation principle of GNSS-R technology.Based on the GNSS-R multi-satellite ocean simulation model and the fast parallel computing capability of GPU,the GNSS-R multi-satellite ocean simulator was designed.Finally,the direct and reflected signals generated by the GNSS-R multi-satellite simulator were tested and verified.The results show that the positioning result of the direct signal meets the positioning accuracy requirements;The delay-related power results obtained from the simulated two-satellite reflected signals processing are in good agreement with the theoretical model,and the correlation coefficients are all above 0.99;The generated signals are used for GNSS-R height measurement technology,the height measurement error is about 1.4~1.8 m,which is in line with the accuracy of the C/A code ranging receiver;And the parallel operation of the GPU for multi-satellite simulation calculation is 800—900 times higher than the traditional CPU calculation.It proves that the proposed model and the designed simulator are feasible and accurate.
文摘A scheme is proposed to elevate the limitation of the ground application system of mono-satellite-sensor under the requirement of remote sensing satellite ground application system.In the resource-sharing, for instance caculating resource, a simple phototype of caculating-resource is proposed through analyzing resource assignment, application assignment, body structure, and so on. In order to improve the ability of assignment, realize the favorable utility, management,and maintenance, the phototype is improved by using datagrid calculation according to the requirement and character of actual application. The phototype can be taken as the foundation of calculation frame of remote sensing ground application system of multi-satellite and multi-sensor.
文摘针对光伏发电、水电及风电联合运行时电量外送因输电断面限额导致的弃水问题,分析了线路输电断面限额的机理,建立了考虑输电断面极限传输容量(Total Transfer Capability,TTC)以外送电量最大为目标,基于采用两时段滑动寻优算法(Progressive Optimization Algorithm,POA)的光伏发电、水电及风电联合运行长期优化调度模型,利用水电站的库容储能进行调峰,提高输电线路的使用率。仿真算例证明,所提模型具有较高可行性和有效性。
