基于Sentinel-3数据计算多年条件植被温度指数(I VTC),并进行近实时定量干旱监测,以陕西省关中平原为研究区,在单年Sentinel-3数据的基础上综合多年Terra MODIS数据计算多年Sentinel-3 I VTC,进而实现研究区的干旱监测。研究结果表明,...基于Sentinel-3数据计算多年条件植被温度指数(I VTC),并进行近实时定量干旱监测,以陕西省关中平原为研究区,在单年Sentinel-3数据的基础上综合多年Terra MODIS数据计算多年Sentinel-3 I VTC,进而实现研究区的干旱监测。研究结果表明,基于单年Terra MODIS I VTC与多年Terra MODIS I VTC之间的线性回归模型计算关中平原的多年Sentinel-3 I VTC是可行的,并且计算的旬尺度多年Sentinel-3 I VTC与近20 d累积降水量具有较高的相关性,相关系数(R 2)达到0.65,展现了较高的近实时定量干旱监测能力。展开更多
The ocean and land color instrument(OLCI) and synthetic aperture radar altimeter(SRAL) installed aboard the Sentinel-3 satellite have been in orbit for operational uses. In this study, data collected from Sentinel-3 a...The ocean and land color instrument(OLCI) and synthetic aperture radar altimeter(SRAL) installed aboard the Sentinel-3 satellite have been in orbit for operational uses. In this study, data collected from Sentinel-3 are used to investigate internal waves in the South China Sea. An internal wave is detected using an OLCI image with a resolution of 300 m, and an analysis was performed with a quasi-synchronous moderate-resolution imaging spectroradiometer(MODIS) image. The opposite characteristics of OLCI and MODIS images of the same internal wave are explained by the critical angle in brightness reversals. The unique observational geometry of the OLCI image and its influence on observations of internal waves are discussed. The distribution of σ0 and sea surface height anomalies(SSHAs) induced by internal waves are studied using SRAL records. The σ0 records of SRAL occasionally show less sensitivity to the modulation of internal waves, which may be attributed to the observational geometry, while SSHAs show obvious variations. The synchronous pairing of OLCI images and SRAL records are analyzed to extract the three-dimensional sea surface signatures induced by internal waves. The analysis demonstrates that the profile of SSHAs in the surface shows an opposite phase to the profiles of internal waves in the ocean. The opposite phase relationship, observed in the remote sensing view, is also confirmed with a laboratory experiment.展开更多
In this study,the north-western Pacific Ocean of Kuroshio region is selected as the experimental area to analyze the mesoscale eddies observation abilities of Sentinel-3 A SRAL,including the independent detection abil...In this study,the north-western Pacific Ocean of Kuroshio region is selected as the experimental area to analyze the mesoscale eddies observation abilities of Sentinel-3 A SRAL,including the independent detection abilities of Sentinel-3 A SRAL and the improvement of mesoscale eddies detection abilities by data fusion with other satellite altimetry data.The Sentinel-3 A SRAL data are mapped by the spatial-temporal objective analysis method to the sea level anomaly grid data.The mapping errors are analyzed by the comparisons between the grid data of different combinations and along the ground track of Jason-2/3.The independent detection abilities of Sentinel-3 A SRAL are analyzed by the comparison between the grid data and the AVISO MSLA data.On the other hand,through the multi-satellite data fusion of different combinations of Sentinel-3 A altimeter and other satellite altimeters such as Jason-2/3,the mesoscale eddies detection was performed based on the merged sea level anomaly data and the addition of Sentinel-3 A SRAL data for the improvements of mesoscale eddies detection abilities by multi-satellite altimeters are concluded.It is concluded that Sentinel-3 A SRAL has good abilities of mesoscale eddies detection as the combination of Jason-2 and Jason-3,and it is better than that of single altimeter of Jason-2 or Jason-3.展开更多
文摘基于Sentinel-3数据计算多年条件植被温度指数(I VTC),并进行近实时定量干旱监测,以陕西省关中平原为研究区,在单年Sentinel-3数据的基础上综合多年Terra MODIS数据计算多年Sentinel-3 I VTC,进而实现研究区的干旱监测。研究结果表明,基于单年Terra MODIS I VTC与多年Terra MODIS I VTC之间的线性回归模型计算关中平原的多年Sentinel-3 I VTC是可行的,并且计算的旬尺度多年Sentinel-3 I VTC与近20 d累积降水量具有较高的相关性,相关系数(R 2)达到0.65,展现了较高的近实时定量干旱监测能力。
基金The National Key R&D Program of China under contract No. 2016YFC1401005the National Youth Natural Science Foundation of China under contract Nos 41906157 and 61501130+1 种基金the National Natural Science Foundation of China under contract No. 61471136the Global Change and Air-Sea Interaction Program of China under contract No. GASI-02-SCS-YGST2-04.
文摘The ocean and land color instrument(OLCI) and synthetic aperture radar altimeter(SRAL) installed aboard the Sentinel-3 satellite have been in orbit for operational uses. In this study, data collected from Sentinel-3 are used to investigate internal waves in the South China Sea. An internal wave is detected using an OLCI image with a resolution of 300 m, and an analysis was performed with a quasi-synchronous moderate-resolution imaging spectroradiometer(MODIS) image. The opposite characteristics of OLCI and MODIS images of the same internal wave are explained by the critical angle in brightness reversals. The unique observational geometry of the OLCI image and its influence on observations of internal waves are discussed. The distribution of σ0 and sea surface height anomalies(SSHAs) induced by internal waves are studied using SRAL records. The σ0 records of SRAL occasionally show less sensitivity to the modulation of internal waves, which may be attributed to the observational geometry, while SSHAs show obvious variations. The synchronous pairing of OLCI images and SRAL records are analyzed to extract the three-dimensional sea surface signatures induced by internal waves. The analysis demonstrates that the profile of SSHAs in the surface shows an opposite phase to the profiles of internal waves in the ocean. The opposite phase relationship, observed in the remote sensing view, is also confirmed with a laboratory experiment.
基金Chinese National Natural Science Foundation(No.41576176)。
文摘In this study,the north-western Pacific Ocean of Kuroshio region is selected as the experimental area to analyze the mesoscale eddies observation abilities of Sentinel-3 A SRAL,including the independent detection abilities of Sentinel-3 A SRAL and the improvement of mesoscale eddies detection abilities by data fusion with other satellite altimetry data.The Sentinel-3 A SRAL data are mapped by the spatial-temporal objective analysis method to the sea level anomaly grid data.The mapping errors are analyzed by the comparisons between the grid data of different combinations and along the ground track of Jason-2/3.The independent detection abilities of Sentinel-3 A SRAL are analyzed by the comparison between the grid data and the AVISO MSLA data.On the other hand,through the multi-satellite data fusion of different combinations of Sentinel-3 A altimeter and other satellite altimeters such as Jason-2/3,the mesoscale eddies detection was performed based on the merged sea level anomaly data and the addition of Sentinel-3 A SRAL data for the improvements of mesoscale eddies detection abilities by multi-satellite altimeters are concluded.It is concluded that Sentinel-3 A SRAL has good abilities of mesoscale eddies detection as the combination of Jason-2 and Jason-3,and it is better than that of single altimeter of Jason-2 or Jason-3.
