IMOS - SRS Satellite Altimetry Calibration and Validation Sub-Facility

IMOS - SRS 卫星测高校准和验证子设施

• 批准号: global : 78d588ed-79dd-47e2-b806-d39025194e7e
• 负责人: Watson, Christopher
• 金额: --
• 依托单位国家: 澳大利亚
• 财政年份: 2008
• 资助国家: 澳大利亚
• 起止时间: 2008-01-01 至 无数据
• 项目状态: 已结题
• 来源: https://researchdata.edu.au/imos-srs-satellite-sub-facility/476857
• 关键词: IMOS; SRS; Satellite; Altimetry; Calibration

High precision satellite altimeter missions including TOPEX/Poseidon (T/P), Jason-1 and now OSTM/Jason-2, have contributed fundamental advances in our understanding of regional and global ocean circulation and its role in the Earth's climate and regional applications. These altimeter satellites essentially observe the height of the global oceans – as such, they have become the tool of choice for scientists to measure sea level rise – both at regional and global scales as well as giving information about ocean currents and large- and small-scale variability. The determination of changes in global mean sea level is of fundamental importance in understanding the response of the ocean to a continuing warming climate – both through thermal expansion of the ocean, melting of the major ice sheets of Greenland and Antarctica, and mountain glaciers, and redistribution of water over the continents and atmosphere. As with all scientific observations, it is vital that the measurement tool is operating within its specifications – calibration and validation is therefore an important component in this regard. <br /> <br /> This IMOS sub-facility provides the sole southern hemisphere in situ calibration site to provide an ongoing calibration and validation data stream directly to the international (NASA and CNES sponsored) Ocean Surface Topography Science Team (OSTST). This contribution, importantly, spans multiple altimeter missions, thus enabling the assimilation of multi-mission satellite data to determine ongoing changes in sea level with flow-on effects to other uses of this data. The OSTST collectively oversees the operation and calibration of the precision altimetry missions, and ensures each of these missions is performing as accurately as possible in order to meet mission objectives. The IMOS supported calibration site in Australia is one of four primary in situ calibration/validation sites that contribute to the OSTST. The remaining sites include Harvest (USA), Corsica (France), and Gavdos (Greece). The Australian calibration site includes two comparison points where in situ data is compared against the altimeter – Bass Strait and Storm Bay. These two locations both lie on descending (N -&gt; S) pass 088 of the satellite altimeter, and thus share similar satellite orbit characteristics. The use of these two sites allows detailed investigation into the accuracy of the altimeter over two different wave climates. The average significant wave height at Storm Bay is approximately double that observed at the comparatively sheltered Bass Strait location. One of the ongoing issues with satellite altimeter missions is the “Sea-state bias” correction which is related to wave shape and height. We plan to use the different wave climates at the two locations, coupled with the fact that some other things (such as orbit errors) are the same at both locations to improve the quality of this correction.

包括TOPEX/Poseidon（T/P），Jason-1和现在的OSTM/Jason-2在内的高精度卫星高度计任务为我们了解区域和全球海洋环流及其在地球气候和区域应用中的作用做出了根本性的进步。这些高度计卫星基本上观察全球海洋的高度-因此，它们已成为科学家在区域和全球范围内测量海平面上升的首选工具，并提供有关洋流和大尺度和小尺度变化的信息。确定全球平均海平面的变化对于理解海洋对持续变暖气候的反应至关重要-海洋的热膨胀、格陵兰岛和南极洲的主要冰盖和山地冰川的融化，以及水在大陆和大气中的重新分布。与所有科学观测一样，测量工具在其规格范围内运行至关重要-因此，校准和验证是这方面的重要组成部分。<br /> <br /> 国际海洋观测系统的这一分设施是南半球唯一的现场校准场地，可直接向国际（美国航天局和法国国家空间研究中心赞助的）海洋表面地形科学小组提供持续的校准和验证数据流。重要的是，这种贡献跨越多个高度计任务，从而能够同化多任务卫星数据，以确定海平面的持续变化，并对这些数据的其他用途产生影响。OSTST共同监督精密测高任务的操作和校准，并确保这些任务中的每一个都尽可能准确地执行，以满足使命目标。国际海洋观测系统支持的澳大利亚校准站是对外层空间技术测试作出贡献的四个主要现场校准/验证站之一。其余研究中心包括Harvest（美国）、科西嘉（法国）和Gavdos（希腊）。澳大利亚的校准地点包括两个比较点，将现场数据与高度计进行比较-巴斯海峡和风暴湾。这两个位置都位于卫星高度计的下降（N-S）通道088上，因此具有相似的卫星轨道特征。这两个站点的使用允许对高度计在两种不同波浪气候下的准确性进行详细调查。风暴湾的平均有效波高大约是在相对隐蔽的巴斯海峡位置观察到的波高的两倍。卫星高度计任务的一个持续问题是与波浪形状和高度有关的“海况偏差”校正。我们计划利用两个地点不同的波浪气候，再加上两个地点的其他一些东西（如轨道误差）是相同的，以提高这种校正的质量。