在流体静力平衡状态下,海洋Coriolis力和压力梯度平衡就形成地转流,世界上大多数海流都近似为地转流.本文利用卫星测高交叉点方法计算海洋表面地转流速度,分析了利用测高交叉点计算地转流速度的不确定性,上升和下降弧段的海面倾斜在分辨...在流体静力平衡状态下,海洋Coriolis力和压力梯度平衡就形成地转流,世界上大多数海流都近似为地转流.本文利用卫星测高交叉点方法计算海洋表面地转流速度,分析了利用测高交叉点计算地转流速度的不确定性,上升和下降弧段的海面倾斜在分辨率50km上可以达到10^(-7)量级,才可能获得优于10cm/s的地转流速度.在低纬度或者纬度接近卫星轨道倾角的地区,由交叉点方法计算的地转流速度精度低于中纬度地区.以中国台湾东部黑潮为试验区,利用最新的中国台湾周边海域大地水准面模型参考场计算高精度的大地水准面高,利用TOPEX/Poseidon和Jason-1的GDR数据(2002～2005年)计算海面高,然后计算交叉点的动力高,确定交叉点的地转流速度,结果与中国台湾NCOR(National Center for Ocean Research)的流速基本一致.展开更多
This research aims to optimize the utilization of long-term sea level data from the TOPEX/Poseidon,Jason1,Jason2,and Jason3 altimetry missions for tidal modeling.We generate a time series of along-track observations a...This research aims to optimize the utilization of long-term sea level data from the TOPEX/Poseidon,Jason1,Jason2,and Jason3 altimetry missions for tidal modeling.We generate a time series of along-track observations and apply a developed method to produce tidal models with specific tidal constituents for each location.Our tidal modeling methodology follows an iterative process:partitioning sea surface height(SSH)observations into analysis/training and prediction/validation parts and ultimately identi-fying the set of tidal constituents that provide the best predictions at each time series location.The study focuses on developing 1256 time series along the altimetry tracks over the Baltic Sea,each with its own set of tidal constituents.Verification of the developed tidal models against the sSH observations within the prediction/validation part reveals mean absolute error(MAE)values ranging from 0.0334 m to 0.1349 m,with an average MAE of 0.089 m.The same validation process is conducted on the FES2014 and EOT20 global tidal models,demonstrating that our tidal model,referred to as BT23(short for Baltic Tide 2023),outperforms both models with an average MAE improvement of 0.0417 m and 0.0346 m,respectively.In addition to providing details on the development of the time series and the tidal modeling procedure,we offer the 1256 along-track time series and their associated tidal models as supplementary materials.We encourage the satellite altimetry community to utilize these resources for further research and applications.展开更多
The joint US/French Jason-1 satellite altimeter mission, launched from the Vandenberg Air Force Base on December 7, 2001, continues the time series of centimeter-level ocean topography observations as the follow-on to...The joint US/French Jason-1 satellite altimeter mission, launched from the Vandenberg Air Force Base on December 7, 2001, continues the time series of centimeter-level ocean topography observations as the follow-on to the highly successful T/P radar altimeter satellite. Orbit error especially the radial orbit error is a major component in the overall budget of all altimeter satellite missions, in order to continue the T/P standard of observations. Jason-1 has a radial orbit error budget requirement of 2.5 cm. In this work, two cycles (December 19, 2002 to January 7, 2003) of the Jason-1 on-board GPS data were processed using the zero-difference (ZD) dynamic precise orbit determination (POD) technique. The resulting Jason-1 orbit accuracy was assessed by comparison with the precise orbit ephemeris (POE) produced by JPL, orbit overlaps and SLR residuals. These evaluations indicate that the RMS radial accuracy is in the range of 1-2 cm.展开更多
海况偏差(Sea State Bias,SSB)是卫星高度计测量海表面高度主要的误差源之一.本文采用Jason-1高度计Ku波段cycle060-cycle140的地球物理数据(GDR),基于泰勒展开公式对海况偏差构造以有效波高和风速为变量的32种参数模型.对测高数据进行...海况偏差(Sea State Bias,SSB)是卫星高度计测量海表面高度主要的误差源之一.本文采用Jason-1高度计Ku波段cycle060-cycle140的地球物理数据(GDR),基于泰勒展开公式对海况偏差构造以有效波高和风速为变量的32种参数模型.对测高数据进行编辑,根据海面高、有效波高和风速对所有模型参数进行求解,对求得的模型进行决定系数检验,获得最优的六参数模型.通过将六参数模型的海况偏差校正值与Jason-1高度计GDR数据的非参数模型海况偏差校正值相对比,计算两者互差的rms为1.47 cm,说明六参数模型的海况偏差估计值和非参数模型的海况偏差整体吻合度较好.利用交叉点处海面高不符值和验潮站数据分析六参数模型的海况偏差估计值改正后的海面高观测精度.六参数模型的海况偏差估计值可以将交叉点海面高不符值的rms降低0.001 m.在其他条件都相同的情况下,六参数模型得到的海况偏差估计值改正后的海面高与验潮站数据差值的标准差以及相关系数均略优于GDR中非参数模型的海况偏差改正的海面高与验潮站数据的差值.所以本文的海况偏差六参数模型可以提高雷达高度计的测高精度.展开更多
文摘在流体静力平衡状态下,海洋Coriolis力和压力梯度平衡就形成地转流,世界上大多数海流都近似为地转流.本文利用卫星测高交叉点方法计算海洋表面地转流速度,分析了利用测高交叉点计算地转流速度的不确定性,上升和下降弧段的海面倾斜在分辨率50km上可以达到10^(-7)量级,才可能获得优于10cm/s的地转流速度.在低纬度或者纬度接近卫星轨道倾角的地区,由交叉点方法计算的地转流速度精度低于中纬度地区.以中国台湾东部黑潮为试验区,利用最新的中国台湾周边海域大地水准面模型参考场计算高精度的大地水准面高,利用TOPEX/Poseidon和Jason-1的GDR数据(2002～2005年)计算海面高,然后计算交叉点的动力高,确定交叉点的地转流速度,结果与中国台湾NCOR(National Center for Ocean Research)的流速基本一致.
文摘This research aims to optimize the utilization of long-term sea level data from the TOPEX/Poseidon,Jason1,Jason2,and Jason3 altimetry missions for tidal modeling.We generate a time series of along-track observations and apply a developed method to produce tidal models with specific tidal constituents for each location.Our tidal modeling methodology follows an iterative process:partitioning sea surface height(SSH)observations into analysis/training and prediction/validation parts and ultimately identi-fying the set of tidal constituents that provide the best predictions at each time series location.The study focuses on developing 1256 time series along the altimetry tracks over the Baltic Sea,each with its own set of tidal constituents.Verification of the developed tidal models against the sSH observations within the prediction/validation part reveals mean absolute error(MAE)values ranging from 0.0334 m to 0.1349 m,with an average MAE of 0.089 m.The same validation process is conducted on the FES2014 and EOT20 global tidal models,demonstrating that our tidal model,referred to as BT23(short for Baltic Tide 2023),outperforms both models with an average MAE improvement of 0.0417 m and 0.0346 m,respectively.In addition to providing details on the development of the time series and the tidal modeling procedure,we offer the 1256 along-track time series and their associated tidal models as supplementary materials.We encourage the satellite altimetry community to utilize these resources for further research and applications.
基金Supported by the National Natural Science Foundation of China (Grant No. 40274006)High-tech Research and Development Program of China (Grant No. 2006AA12A107)Science & Technology Commission of Shanghai Municipality (Grant No. 06DZ22101)
文摘The joint US/French Jason-1 satellite altimeter mission, launched from the Vandenberg Air Force Base on December 7, 2001, continues the time series of centimeter-level ocean topography observations as the follow-on to the highly successful T/P radar altimeter satellite. Orbit error especially the radial orbit error is a major component in the overall budget of all altimeter satellite missions, in order to continue the T/P standard of observations. Jason-1 has a radial orbit error budget requirement of 2.5 cm. In this work, two cycles (December 19, 2002 to January 7, 2003) of the Jason-1 on-board GPS data were processed using the zero-difference (ZD) dynamic precise orbit determination (POD) technique. The resulting Jason-1 orbit accuracy was assessed by comparison with the precise orbit ephemeris (POE) produced by JPL, orbit overlaps and SLR residuals. These evaluations indicate that the RMS radial accuracy is in the range of 1-2 cm.
文摘海况偏差(Sea State Bias,SSB)是卫星高度计测量海表面高度主要的误差源之一.本文采用Jason-1高度计Ku波段cycle060-cycle140的地球物理数据(GDR),基于泰勒展开公式对海况偏差构造以有效波高和风速为变量的32种参数模型.对测高数据进行编辑,根据海面高、有效波高和风速对所有模型参数进行求解,对求得的模型进行决定系数检验,获得最优的六参数模型.通过将六参数模型的海况偏差校正值与Jason-1高度计GDR数据的非参数模型海况偏差校正值相对比,计算两者互差的rms为1.47 cm,说明六参数模型的海况偏差估计值和非参数模型的海况偏差整体吻合度较好.利用交叉点处海面高不符值和验潮站数据分析六参数模型的海况偏差估计值改正后的海面高观测精度.六参数模型的海况偏差估计值可以将交叉点海面高不符值的rms降低0.001 m.在其他条件都相同的情况下,六参数模型得到的海况偏差估计值改正后的海面高与验潮站数据差值的标准差以及相关系数均略优于GDR中非参数模型的海况偏差改正的海面高与验潮站数据的差值.所以本文的海况偏差六参数模型可以提高雷达高度计的测高精度.
