Stability of ERS altimetry during the Tandem Mission
Stability of ERS altimetry during the Tandem Mission
复制标题
串联任务期间 ERS 测高的稳定性
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
R. Walmsley
中科院分区：
文献类型：
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作者：
P. Moore;S. Carnochan;R. Walmsley
如果系统误差不被混淆到解决方案中，那么来自高度测量任务的海平面变化研究需要精确的校准。对于ERS-2，现在有越来越多的证据表明高度范围是有偏差的。对ERS-1、ERS-2和TOPEX/Poseidon同时运行期间的全球研究表明，包括空间效应在内，ERS-1和TOPEX的平均海平面上升分别为-4.7 mm/年和-5.6 mm/年，但ERS-2为9.0 mm/年。此外，ERS-1和ERS-2之间的重复通过数据产生了相当于11 mm/年斜率的系统差异。结果表明，重复通过数据中的不连续性对应于仪器异常后ERS高度计被关闭。尽管使用了用户社区可用的校正数据，但仍会出现这些不连续性。ERS高度计长期系统误差的修正是通过使用TOPEX的双卫星交叉残差确定的。这些增强消除了虚假趋势，ERS-1和ERS-2之间的差异斜率降低到0.2 mm/年。由于大部分修正都是由ERS-2引起的，因此很明显，这颗卫星比ERS-1更有问题。
Studies of sea‐level change from altimetric missions require accurate calibration if systematic errors are not to be aliased into the solution. For ERS‐2 there is now growing evidence that the altimetric range is biased. Global studies over the period of concurrent operation of ERS‐1, ERS‐2 and TOPEX/Poseidon show that the mean sea‐level rise, including the steric effect, was −4.7 mm/yr and −5.6 mm/yr for ERS‐1 and TOPEX respectively but 9.0 mm/yr for ERS‐2. Further, repeat pass data between ERS‐1 and ERS‐2 yields a systematic difference equivalent to a 11 mm/yr slope. The results show that discontinuities in the repeat pass data correspond to the ERS altimeters being switched off after an instrument anomaly. These discontinuities occur despite utilisation of the correction data available to the user community. Corrections to the long‐term systematic errors in the ERS altimeters have been determined by using dual satellite crossover residuals with TOPEX. These enhancements remove the spurious trend to the extent that the differential slope between ERS‐1 and ERS‐2 is reduced to 0.2 mm/yr. With most of the correction attributable to ERS‐2 it is apparent that this satellite is more problematic than ERS‐1.