The HY-2 satellite was successfully launched on 16 August 2011.It carried four microwave instruments into space for operationally observing dynamic ocean environment parameters on a global scale.The HY-2 satellite alt...The HY-2 satellite was successfully launched on 16 August 2011.It carried four microwave instruments into space for operationally observing dynamic ocean environment parameters on a global scale.The HY-2 satellite altimeter provides sea surface height(SSH),significant wave height(SWH),sea surface wind(SSW)speed,and polar ice sheet elevation,while the HY-2 satellite scatterometer provides SSW fields.At the same time,other oceanic and atmospheric parameters such as sea surface temperature(SST)and wind speed,water vapor and liquid water content can also be obtained by its onboard scanning microwave radiometer.In this paper,we show the data processing methods of the HY-2 satellite’s payloads.The preliminary results show that wind vector,SSH,SWH,and SST conform to the designed technical specifications.展开更多
The first Chinese microwave ocean environment satellite HY-2A, carrying a Ku-band scatteromenter （SCAT）, was successfully launched in August 2011. The first quality assessment of HY-2A SCAT wind products is presente...The first Chinese microwave ocean environment satellite HY-2A, carrying a Ku-band scatteromenter （SCAT）, was successfully launched in August 2011. The first quality assessment of HY-2A SCAT wind products is presented through the comparison of the first 6 months operationally released SCAT products with in situ data. The in situ winds from the National Data Buoy Center （NDBC） buoys, R/V Polarstern, Aurora Australis, Roger Revelle and PY30-1 oil platform, were converted to the 10 m equivalent neutral winds. The temporal and spatial differences between the HY-2A SCAT and the in situ observations were limited to less than 5 min and 12.5 km. For HY-2A SCAT wind speed products, the comparison and analysis using the NDBC buoys yield a bias of-0.49 m/s, a root mean square error （RMSE） of 1.3 m/s and an increase negative bias with increasing wind speed observation above 3 m/s. Although less accurate of HY-2A SCAT wind direction at low winds, the RMSE of 19.19° with a bias of 0.92° is found for wind speeds higher than 3 m/s. These results are found consistent with those from R/Vs and oil platform comparisons. Moreover, the NDBC buoy comparison results also suggest that the accuracy of HY-2A SCAT winds is consistent over the first half year of 2012. The encouraging assessment results over the first 6 months show that wind products from HY-2A SCAT will be useful for scientific community.展开更多
星载微波散射计是获取全球海面风场信息的主要手段,HY-2B卫星散射计的成功发射为全球海面风场数据获取的持续性提供了重要保障。本文利用欧洲中期天气预报中心(EuropeanCenter forMedium-RangeWeatherForecasts,ECMWF)再分析风场数据、...星载微波散射计是获取全球海面风场信息的主要手段,HY-2B卫星散射计的成功发射为全球海面风场数据获取的持续性提供了重要保障。本文利用欧洲中期天气预报中心(EuropeanCenter forMedium-RangeWeatherForecasts,ECMWF)再分析风场数据、热带大气海洋观测计划(TropicalAtmosphereOceanArray,TAO)和美国国家数据浮标中心(National Data Buoy Center,NDBC)浮标获取的海面风矢量实测数据,对HY-2B散射计海面风场数据产品的质量进行统计分析。分析表明,HY-2B风场与ECMWF再分析风场对比,在4~24m·s^-1风速区间内,风速和风向均方根误差(root mean squareerror,RMSE)分别为1.58m·s^-1和15.34°;与位于开阔海域的TAO浮标数据对比,风速、风向RMSE分别为1.03m·s^-1和14.98°,可见HY-2B风场能较好地满足业务化应用的精度要求(风速优于2m·s^-1,风向优于20°)。与主要位于近海海域的NDBC浮标对比,HY-2B风场的风速、风向RMSE分别为1.60m·s^-1和19.14°,说明HY-2B散射计同时具备了对近海海域风场的良好观测能力。本文还发现HY-2B风场质量会随风速、地面交轨位置等变化,为用户更好地使用HY-2B风场产品提供参考。展开更多
The typhoon, as a mature tropical cyclone that develops in the western part of the North Pacific Ocean with high wind speed and heavy rainfall, is one of the most lethal and costly of natural disasters for the densely...The typhoon, as a mature tropical cyclone that develops in the western part of the North Pacific Ocean with high wind speed and heavy rainfall, is one of the most lethal and costly of natural disasters for the densely populated countries of East Asia. It can be easily detected by space-borne sensors operated at microwave, visible or infrared bands （Liu et al., 2014）. Synthetic Aperture Radar （SAR） is a kind of active imaging radar, which can detect the targets with high resolution at one-meter level. SARs can be used to extract the sea surface wind and the eyes of typhoons or hurricanes （Friedman and Li, 2000; Zhang and Perrie, 2012; Li, 2015; Jin et al., 2014; Liu et al., 2014）. As a pioneer project of Haiyang-3 （HY-3）, the Chinese C-band SAR satellite of Gaofen-3 （GF-3） was launched in August 2016 under China High-resolution Earth Observation System （CEOS）. GF-3 carries a multi-polarized C-band SAR with a highest spatial resolution of one meter, the most imaging modes in the word of twelve and a long designed lifespan of 8 years. Haiyang-2A （HY-2A）, which was launched in August 2011, is the first Chinese marine dynamic environment satellite with a main payload of Ku-band microwave scatterometer （Jiang et al., 2012; Ye et al., 2015）. One of the objectives of HY-2A scatterometer （HY-2A SCAT） is monitoring sea surface wind field of global ocean.展开更多
The Chinese marine dynamic environment satellite HY-2B was launched in October 2018 and carries a Ku-band scatterometer.This paper focuses on the accuracies of HY-2B scatterometer wind data during the period from Nove...The Chinese marine dynamic environment satellite HY-2B was launched in October 2018 and carries a Ku-band scatterometer.This paper focuses on the accuracies of HY-2B scatterometer wind data during the period from November 2018 to May 2021.The HY-2B wind data are validated against global moored buoys operated by the U.S.National Data Buoy Center and Tropical Atmosphere Ocean,numerical model data by the National Centers for Environmental Prediction,and the Advanced Scatterometer data issued by the Remote Sensing System.The results showed that the wind speeds and directions observed by the HY-2B scatterometer agree well with these buoy wind measurements.The root-mean-squared errors(RMSEs)of the HY-2B wind speed and direction are 0.74 m/s and 11.74°,respectively.For low wind speeds(less than 5 m/s),the standard deviation of the HY-2B-derived wind direction is higher than 20°,which implies that the HY-2B wind direction for low wind speeds is less accurate than that for moderate to high wind speed ranges.The RMSE of the HY-2B wind speed is slightly larger in high latitude oceans(60°–90°S and 60°–90°N)than in low latitude regions.Furthermore,the dependence of the residuals on the cross-track location of wind vector cells and the stability of the HY-2B scatterometer wind products are discussed.The wind stability assessment results indicate that a clear yearly oscillation is observed for the HY-2B wind speed bias which is due to seasonal weather variations.In general,the accuracy of HY-2B winds meets the operational precision requirement and is consistent with other wind data.展开更多
研究利用神经网络方法处理微波散射计数据,反演海面风场。重点研究海洋二号(HY-2)卫星微波散射计数据反演,特别是中高风速条件下的风场反演。其中风速的反演基于后向传播(Back Propagation,BP)神经网络;多解风向的反演基于混合密度(Mixt...研究利用神经网络方法处理微波散射计数据,反演海面风场。重点研究海洋二号(HY-2)卫星微波散射计数据反演,特别是中高风速条件下的风场反演。其中风速的反演基于后向传播(Back Propagation,BP)神经网络;多解风向的反演基于混合密度(Mixture Density Network,MDN)神经网络,求解过程中的核函数采用高斯分布;网络训练的目标风场采用欧洲中期天气预报中心(European Centre for Medium-range Weather Foresting,ECMWF)模式风场。通过与ECMWF风场的比较,利用神经网络方法反演的风场可以满足HY-2微波散射计风场反演的精度要求。同时通过与国家卫星海洋应用中心发布的HY-2微波散射计L2B级风场产品相比较,表明该方法反演的风场更接近ECMWF模式风场。展开更多
基金supported by the National High-Tech Project of China(No.2008AA09A403)the Marine Public Welfare Project of China(No.201105032).
文摘The HY-2 satellite was successfully launched on 16 August 2011.It carried four microwave instruments into space for operationally observing dynamic ocean environment parameters on a global scale.The HY-2 satellite altimeter provides sea surface height(SSH),significant wave height(SWH),sea surface wind(SSW)speed,and polar ice sheet elevation,while the HY-2 satellite scatterometer provides SSW fields.At the same time,other oceanic and atmospheric parameters such as sea surface temperature(SST)and wind speed,water vapor and liquid water content can also be obtained by its onboard scanning microwave radiometer.In this paper,we show the data processing methods of the HY-2 satellite’s payloads.The preliminary results show that wind vector,SSH,SWH,and SST conform to the designed technical specifications.
基金The Marine Public Welfare Project of China under contract No.201105032the National High-Tech Project of China under contract No.2008AA09A403the fund of State Administration for Science,Technology and Industry for National Defense
文摘The first Chinese microwave ocean environment satellite HY-2A, carrying a Ku-band scatteromenter （SCAT）, was successfully launched in August 2011. The first quality assessment of HY-2A SCAT wind products is presented through the comparison of the first 6 months operationally released SCAT products with in situ data. The in situ winds from the National Data Buoy Center （NDBC） buoys, R/V Polarstern, Aurora Australis, Roger Revelle and PY30-1 oil platform, were converted to the 10 m equivalent neutral winds. The temporal and spatial differences between the HY-2A SCAT and the in situ observations were limited to less than 5 min and 12.5 km. For HY-2A SCAT wind speed products, the comparison and analysis using the NDBC buoys yield a bias of-0.49 m/s, a root mean square error （RMSE） of 1.3 m/s and an increase negative bias with increasing wind speed observation above 3 m/s. Although less accurate of HY-2A SCAT wind direction at low winds, the RMSE of 19.19° with a bias of 0.92° is found for wind speeds higher than 3 m/s. These results are found consistent with those from R/Vs and oil platform comparisons. Moreover, the NDBC buoy comparison results also suggest that the accuracy of HY-2A SCAT winds is consistent over the first half year of 2012. The encouraging assessment results over the first 6 months show that wind products from HY-2A SCAT will be useful for scientific community.
文摘星载微波散射计是获取全球海面风场信息的主要手段,HY-2B卫星散射计的成功发射为全球海面风场数据获取的持续性提供了重要保障。本文利用欧洲中期天气预报中心(EuropeanCenter forMedium-RangeWeatherForecasts,ECMWF)再分析风场数据、热带大气海洋观测计划(TropicalAtmosphereOceanArray,TAO)和美国国家数据浮标中心(National Data Buoy Center,NDBC)浮标获取的海面风矢量实测数据,对HY-2B散射计海面风场数据产品的质量进行统计分析。分析表明,HY-2B风场与ECMWF再分析风场对比,在4~24m·s^-1风速区间内,风速和风向均方根误差(root mean squareerror,RMSE)分别为1.58m·s^-1和15.34°;与位于开阔海域的TAO浮标数据对比,风速、风向RMSE分别为1.03m·s^-1和14.98°,可见HY-2B风场能较好地满足业务化应用的精度要求(风速优于2m·s^-1,风向优于20°)。与主要位于近海海域的NDBC浮标对比,HY-2B风场的风速、风向RMSE分别为1.60m·s^-1和19.14°,说明HY-2B散射计同时具备了对近海海域风场的良好观测能力。本文还发现HY-2B风场质量会随风速、地面交轨位置等变化,为用户更好地使用HY-2B风场产品提供参考。
基金The National Key R&D Program of China under contract No.2016YFC1401000the Joint Foundation of National Natural Science Foundation of China and the Marine Science Center of Shandong Province under contract No.U1406404the National Natural Science Foundation of China under contract Nos 1506206 and 41476152
文摘The typhoon, as a mature tropical cyclone that develops in the western part of the North Pacific Ocean with high wind speed and heavy rainfall, is one of the most lethal and costly of natural disasters for the densely populated countries of East Asia. It can be easily detected by space-borne sensors operated at microwave, visible or infrared bands （Liu et al., 2014）. Synthetic Aperture Radar （SAR） is a kind of active imaging radar, which can detect the targets with high resolution at one-meter level. SARs can be used to extract the sea surface wind and the eyes of typhoons or hurricanes （Friedman and Li, 2000; Zhang and Perrie, 2012; Li, 2015; Jin et al., 2014; Liu et al., 2014）. As a pioneer project of Haiyang-3 （HY-3）, the Chinese C-band SAR satellite of Gaofen-3 （GF-3） was launched in August 2016 under China High-resolution Earth Observation System （CEOS）. GF-3 carries a multi-polarized C-band SAR with a highest spatial resolution of one meter, the most imaging modes in the word of twelve and a long designed lifespan of 8 years. Haiyang-2A （HY-2A）, which was launched in August 2011, is the first Chinese marine dynamic environment satellite with a main payload of Ku-band microwave scatterometer （Jiang et al., 2012; Ye et al., 2015）. One of the objectives of HY-2A scatterometer （HY-2A SCAT） is monitoring sea surface wind field of global ocean.
基金The National Key Research and Development Program of China under contract No.2021YFB3900400.
文摘The Chinese marine dynamic environment satellite HY-2B was launched in October 2018 and carries a Ku-band scatterometer.This paper focuses on the accuracies of HY-2B scatterometer wind data during the period from November 2018 to May 2021.The HY-2B wind data are validated against global moored buoys operated by the U.S.National Data Buoy Center and Tropical Atmosphere Ocean,numerical model data by the National Centers for Environmental Prediction,and the Advanced Scatterometer data issued by the Remote Sensing System.The results showed that the wind speeds and directions observed by the HY-2B scatterometer agree well with these buoy wind measurements.The root-mean-squared errors(RMSEs)of the HY-2B wind speed and direction are 0.74 m/s and 11.74°,respectively.For low wind speeds(less than 5 m/s),the standard deviation of the HY-2B-derived wind direction is higher than 20°,which implies that the HY-2B wind direction for low wind speeds is less accurate than that for moderate to high wind speed ranges.The RMSE of the HY-2B wind speed is slightly larger in high latitude oceans(60°–90°S and 60°–90°N)than in low latitude regions.Furthermore,the dependence of the residuals on the cross-track location of wind vector cells and the stability of the HY-2B scatterometer wind products are discussed.The wind stability assessment results indicate that a clear yearly oscillation is observed for the HY-2B wind speed bias which is due to seasonal weather variations.In general,the accuracy of HY-2B winds meets the operational precision requirement and is consistent with other wind data.
文摘研究利用神经网络方法处理微波散射计数据,反演海面风场。重点研究海洋二号(HY-2)卫星微波散射计数据反演,特别是中高风速条件下的风场反演。其中风速的反演基于后向传播(Back Propagation,BP)神经网络;多解风向的反演基于混合密度(Mixture Density Network,MDN)神经网络,求解过程中的核函数采用高斯分布;网络训练的目标风场采用欧洲中期天气预报中心(European Centre for Medium-range Weather Foresting,ECMWF)模式风场。通过与ECMWF风场的比较,利用神经网络方法反演的风场可以满足HY-2微波散射计风场反演的精度要求。同时通过与国家卫星海洋应用中心发布的HY-2微波散射计L2B级风场产品相比较,表明该方法反演的风场更接近ECMWF模式风场。
