中国近海TOPEX／POSEIDON卫星测高数据处理的初步结果

本文分析处理了ＴＯＰＥＸ／ＰＯＳＥＩＤＯＮ卫星１～８２周期的测高数据。重新计算了逆气压改正数；利用共线法计算的ＴＯＰＥＸ和ＰＯＳＥＩＤＯＮ之间相对偏差估值为１９．９±１ｃｍ；将编辑后的海面高与Ｂａｓｉｃ和ＲａＰＰ计算的平均海面高进行比较，发现二者之间存在明显的系统偏差。     

联合多种卫星测高数据分析全球和中国海海平面变化

利用了７年的Ｔ／Ｐ数据（第９周期至第２４９周期）、４年的ＥＲＳ２数据（第０周期至第４４周期）和Ｇｅｏｓａｔ精刻度重复任务（ＥＲＭ）数据,由共线法研究了全球海平面变化和中国海域海平面变化。测高数据的逆气压改正采用了每个周期的平均大气压重新计算,对Ｔ／Ｐ和ＥＲＳ２两种数据源计算的１９９５～１９９９年海平面变化作了相应的比较。     

青藏高原块体相对运动模型的GPS方法确定与分析

利用武汉测绘科技大学在１９９３年、１９９５年观测的两期ＧＰＳ资料,具体分析了青藏高原各块体相对运动情况。目前青藏高原大约以３３．４ｍｍ／ａ,Ｎ３０°Ｅ方向向西伯利亚运动,其中巴颜喀拉块体、羌塘块体、拉萨—冈底斯块体和喜马拉雅块体大约分别以１７．３ｍｍ／ａ±３．１ｍｍ／ａ,Ｎ３５°Ｅ;２５．７ｍｍ／ａ±５．１ｍｍ／ａ,Ｎ３３°Ｅ;３８．９ｍｍ／ａ±６．１ｍｍ／ａ,Ｎ２９°Ｅ;４６．０ｍｍ／ａ±６．２ｍｍ／ａ,Ｎ２７°Ｅ方向朝西伯利亚运动,而西藏块体大约以２８．５ｍｍ／ａ±５．０ｍｍ／ａ速率,Ｎ３１°Ｅ方向朝西伯利亚运动,这些结果与地质结果符合。文中还给出了各块体相对运动的欧拉向量。     

南中国海TOPEX/POSEIDON轨迹交叉点测高数据的潮汐调和分析

讨论了由卫星测高数据进行潮汐分析的混叠问题和分潮的可分辨性;用ＴＯＰＥＸ／ＰＯ－ＳＥＩＤＯＮ海面重复轨迹交叉点测高数据计算南中国海１２个分潮（Ｓａ,Ｓｓａ,Ｍｍ,Ｍｆ,Ｑ１,Ｏ１,Ｐ１,Ｋ１,Ｎ２,Ｍ２,Ｓ２,Ｋ２）的调和常数;用不同方法验证了计算结果的精度,分析表明,分潮的振幅精度和潮高精度已达到±２ｃｍ,四个较大分潮（Ｏ１,Ｐ１,Ｋ１,Ｍ２）的迟角误差不超过±７°。其中Ｏ１,Ｋ１,和Ｍ２与验潮站实测值的最大偏差小于７°;给出了最大的全日和半日分潮（Ｋ１,Ｍ２）的潮波图。     

利用GEOSAT／ERM卫星测高数据计算中国近海海平面

本文利用一年（１９８６年１１月８日～１９８７年１１月１７日）２２个ＥＲＭ周期的ＧＥＯＳＡＴ卫星测高数据计算出中国近海海域（１０５°～１３５°Ｅ，０°～４０°Ｎ）相对于ＧＲＳ８０参考椭球面的１°×１°年平均海平面。该海平面我们称之为ＩＧＧＭＳＳ９５平均海平面。在数据处理过程中，由于采用了混合轨道误差模型及交叠平差技术，极大地消除了在误差中占主要成分的径向轨道误差影响，使得ＩＧＧＭＳＳ９５平均海平面的总体精度达到±２０～３０ｃｍ（ＲＭＳ）水平。与ＯＳＵ９１Ａ重力大地水准面模型相比较可以发现两者具有惊人的一致性。     

卫星高度计反演海面风速——模式函数与应用实例

对迄今为止国际上公开发表的１４ 种卫星高度计反演海面风速的模式函数进行了系统的分析和比较。在此基础上提出了一种“折中”模式函数,用于ＴＯＰＥＸ 资料海面风速反演效果良好。文中对高度计获取的全球海面风速分布特征进行了分析,最后探讨了改善海面风速模式函数反演精度的途径。     

利用卫星测高资料反演中国近海海洋重力

本文利用Ｔｏｐｅｘ／Ｐｏｓｅｉｄｏｎ卫星测高资料,从快速Ｈａｒｔｌｅｙ交换（ＦＨＴ）基本概念入手,给出了Ｈｏｔｉｎｅ公式在平面近似、球面近似、Ｍｏｌｏｄｅｎｓｋｉｉ的 下,反演中国近海海洋重力的数学模型,另对ＦＨＴ处理中所需的坐标转换以及边缘效应等问题进行了讨论。同时,为改善长波特性的重力场信息,引入了Ｍ阶次的ＯＳＵ９１Ａ参考重力场对上述Ｍｏｌｏｄｅｎｓｋｉｉ模型进行了改化。     

测高数据处理中网络化问题的探讨

本文从卫星测高数据处理中网距的选取,数据点的图形结构,网格算子等三个方面加以讨论,提出了频域中数据网格化的方法,最后利用两个周期析Ｔｏｐｅｘ／Ｐｏｓｅｉｄｏｎ卫星测高数据进行计算分析,得出了一些卫星测高数据网格化的经验。     

基于ＳｔａＭＰＳ方法的大坝形变监测可行性研究

利用时序ＩｎＳＡＲ技术的优势,以新疆ＷＬＬ水库大坝为研究对象,使用３１幅Ｓｅｎｔｉｎｅｌ－１Ａ影像,采用ＳｔａＭＰＳ 方法对其进行形变监测,得到大坝及周边区域的形变结果,并从内、外符合精度两个方面进行精度验证。结果表明, 研究区域ＰＳ点平均形变速率标准差区间为０．３～３．１ｍｍ／ａ;ＳｔａＭＰＳ与ＳＢＡＳ形变速率中误差为±５．７ｍｍ;与大 坝二等水准监测成果比较,垂直形变速率中误差为±５．０ｍｍ,垂直累积形变量中误差为±１０．２ｍｍ。从而证明 ＳｔａＭＰＳ方法在大坝形变监测应用中的可行性。     

用T／P测高数据确定中国海域及其邻海的海面高及海面地形

描述了利用Ｔ／Ｐ卫星测高数据确定中国海域及其邻海的海面地形。处理了Ｔ／Ｐ５９～８２周（Ｃｙｃｌｅ）１９９４年第８３ｄ～３１１ｄ的数据，将５９～８２周数据分成两部分分别估计海面高，并分析了海面高变化。结果与Ｂａｓｉｃ和Ｒａｐｐ１９９２年确定的海面高作了比较。利用Ｓｈｅｐａｒｄ曲面拟合方法给出了３０′×３０′平均海面高结果，分别以ＯＳＵ９１和ＷＤＭ９４地球重力场模型作为参考重力场，计算了相应的３０′×３０′平均海面地形。     

卫星测高在陆地湖泊水位变化监测中的应用

本文以呼伦湖为例,利用TOPEX/Poseidon测高卫星(1993～2002年)的GDR和WDR数据以及Jason-1(2002～2005年)的GDR数据对湖泊水位变化进行研究,得到湖泊水位异常的变化趋势。通过利用小波分析的方法对卫星测高获得的湖水位异常时间序列分析,得出了呼伦湖的水位年际变化周期,证明了利用卫星测高进行卫星测高监测湖泊水位变化的可行性。     

抗差最小二乘法在卫星测高数据处理中的应用

在采用1992年10月至1998年10月的Topex/Poseidon卫星测高资料进行海平面变化研究，将抗差最小二乘法引入到数据处理时，计算了平均海面高，海平面变化量和海平面的升降速率及其主要周期项的振幅和相位，同时给出采用经黄最小二乘法计算的结果，将将两种结果进行了比较，最后通过对计算结果的分析，揭示了海平面变化的一些规律，实证了海平面变化与厄尔尼诺现象之间的联系。     

Seasonal sea level change from TOPEX/Poseidon observation and thermal contribution

Seasonal steric sea-level change due to temperature variation in the mixing layer is assessed using space-measured sea-surface temperature data and historical in situ temperature measurements. The results are compared with TOPEX/Poseidon satellite altimeter measurement at different large spatial scales. It is indicated that thermal effect accounts for much of the observed seasonal variability, especially when averaging over zonal regions. Some regional seasonal patterns of sea-level anomalies in the tropical oceans are well represented by the thermal model prediction. Systematic differences are shown between TOPEX/Poseidon observation and thermal contribution at a 1–2 cm level. The potential causes for these differences are discussed, including water mass exchanges among the atmosphere, land, and oceans, and error sources in the steric result and geophysical corrections applied in TOPEX/Poseidon data. Received: 25 September 1998 / Accepted: 13 July 1999     

The ERS-2 altimetric bias and gravity field enhancement using dual crossovers between ERS and TOPEX/Poseidon

 Dual satellite crossovers (DXO) between the two European Remote Sensing satellites ERS-1 and ERS-2 and TOPEX/Poseidon are used to (1) refine the Earth's gravity field and (2) extend the study of the ERS-2 altimetric range stability to cover the first four years of its operation. The enhanced gravity field model, AGM-98, is validated by several methodologies and will be shown to provide, in particular, low geographically correlated orbital error for ERS-2. For the ERS-2 altimetric range study, TOPEX/Poseidon is first calibrated through comparison against in situ tide gauge data. A time series of the ERS-2 altimeter bias has been recovered along with other geophysical correction terms using tables for bias jumps in the range measurements at the single point target response (SPTR) events. On utilising the original version of the SPTR tables the overall bias drift is seen to be 2.6±1.0 mm/yr with an RMS of fit of 12.2 mm but with discontinuities at the centimetre level at the SPTR events. On utilising the recently released revised tables, SPTR2000, the drift is better defined at 2.4±0.6 mm/yr with the RMS of fit reduced to 3.7 mm. Investigations identify the sea-state bias as a source of error with corrections affecting the overall drift by close to 1.2 mm/yr. Received: 25 May 2000 / Accepted: 24 January 2001     

中国近海1992～1998海平面变化监测与分析

利用Topex/Poseidon和ERS-1卫星测高资料采用“共线”法计算出1992-10～1998-06中国近海海域海平面及其变化。在扣除T/P卫星测高仪的零点漂移影响后,发现与全球海平面上升率(+2.1±1.3)mm/a相比,不同海域的海平面变化趋势大不相同,黄、东、南海的海平面年变化率分别为：(+3.44±0.61)mm/a,(+3.12±0.47)mm/a,(-1.41±0.48)mm/a。从海平面变化异常中可以看出1993,1994,1997～1998年3次El Nino异常对中国近海海域海平面的影响是南海海域最大,东海次之,黄海最小。除了对海平面进行传统的频谱分析外,还进行了多分辨率的小波分析,还发现在上述3个海域中除了年周期变化较为稳定外,半年及季节(100 d)周期项存在着时间漂移。此外,在上述3个海域还存在着明显的两个月(62 d)周期的变化,其激发原因在此做了初步探讨。     

Influence of tide models on the use of altimetry data to research sea level anomaly

A tide model (named DN1.0), which contains 12 principal constituents over China seas and the Northwest Pacific is estimated by along-track harmonic analysis with TOPEX/Poseidon altimetry data taken from 1993 to 2002. CSR3.0, FES95.2 and DN1.0 are used respectively to detide the data for the time series of sea level anomaly (SLA) in the Yellow Sea, East China Sea, South China Sea and Northwest Pacific. The SLA curves and the power spectral density show that the major components that exist in SLA in China seas arise from the error of the tide models.     

Influence of Tide Models on the Use of Altimetry Data to Research Sea Level Anomaly

A tide model (named DN1.0), which contains 12 principal constituents over China seas and the Northwest Pacific is estimated by along-track harmonic analysis with TOPEX/Poseidon altimetry data taken from 1993 to 2002. CSR3.0, FES95.2 and DN1.0 are used respectively to detide the data for the time series of sea level anomaly (SLA) in the Yellow Sea, East China Sea, South China Sea and Northwest Pacific. The SLA curves and the power spectral density show that the major components that exist in SLA in China seas arise from the error of the tide models.     

潮汐模型对利用卫星测高数据研究海平面变化的影响

利用T/P测高数据反演了中国近海及西北太平洋海域的潮汐参数,构造了CSR3.0、FES95.2和T/P反演的海潮模型改正下的海面高时间序列,通过海面高变化曲线及功率谱的比较确定了利用测高数据发现的海平面季节内变化主要是潮汐模型误差的贡献.     

Thermosteric Effects on Interannual and Long-term Global Mean Sea Level Changes

We investigate global mean sea level (MSL) changes and different geophysical contributions at interannual and long-term (decadal) time-scales. Thermosteric effects of global MSL changes are estimated from ocean temperature anomaly data for the period 1955–2003 from the World Ocean Database 2001 (WOD01), plus additional data processed through June 2004. Estimates based on WOD01 show significant differences to previously published results based on similar temperature anomaly data from the World Ocean Database 1998 (WOD98), especially during the period overlapping with the TOPEX/Poseidon satellite altimeter mission. During this period (1993–2004), the WOD01-estimated thermosteric contribution of global MSL change is less than half of the estimate from WOD98 (1.3 ± 0.1 vs. 3.0 ± 0.6 mm/year), as compared to the rate of 2.6 ± 0.06 mm/year observed by satellite altimeters. The larger uncertainty in ocean temperature profiles and incomplete data collection in WOD98, especially in the later years (1997 and 1998) appear to be the major error sources to the overestimated steric effects by WOD98. During the entire 50-year period, the steric effect on global MSL change amounts to about 0.34–0.39 (±0.05) mm/year. Strong interannual and decadal variability exists in estimated thermosteric contributions to the global MSL change, and (surprisingly) the thermosteric effect does not show any pronounced contribution to the strong interannual variability during the 1997/1998 El Niño/La Niña event. Our analysis based on the National Centers for Environmental Prediction reanalysis atmospheric model and the National Oceanic and Atmospheric Administration Climate Prediction Center global land data assimilation system indicates that atmospheric water vapor and terrestrial water storage changes show strong interannual variability that is well correlated with observed global MSL change, and could have significant effects on interannual global MSL changes.     

Forecasting sea level anomalies from TOPEX/Poseidon and Jason-1 satellite altimetry

This paper aims at the prediction of both global mean sea level anomalies (SLAs) and gridded SLA data in the east equatorial Pacific obtained from TOPEX/Poseidon and Jason-1 altimetric measurements. The first prediction technique (denoted as LS) is based on the extrapolation of a polynomial-harmonic deterministic least-squares model describing a linear trend, annual and semi-annual oscillations. The second prediction method (denoted as LS + AR) is a combination of the extrapolation of a polynomial-harmonic model with the autoregressive forecast of LS residuals. In the case of forecasting global mean SLA data, both techniques allow one to compute the predictions of comparable accuracy (root mean square error for 1-month in the future is of 0.5 cm). In the case of predicting gridded SLA data, the LS + AR prediction method gains significantly better prediction accuracy than the accuracy obtained by the LS technique during El Niño 1997/1998, La Niña 1998/1999 and during normal conditions.