Success Stories of Satellite Altimeter Applications

For nearly three decades, satellite nadir altimeters have provided essential information to understand, primarily ocean, and also, inland water dynamics. A variety of parameters can be inferred via altimeter measurements, including sea surface height, sea surface wind speeds, significant wave heights, and topography of land and ice sheets. Taking advantage of these parameters with the long record of altimeter data spanning multiple decades has allowed a diverse range of societal applications. As the constellation of altimeter satellites grows, the proven value of the missions to a diverse audience can now be demonstrated by highlighting a selection of verifiable success stories. In this paper, we review twenty altimeter success stories which incorporate altimetry data, alone or in conjunction with numerical models or other earth observations, to solve a key societal problem. First, we define the problem or the key challenge of each use case, and then we articulate the uptake of the successful altimeter-based solution. Our study revealed steady progress by scientific and stakeholder communities in bridging the gap between data availability and their actual uptake to address a variety of applications. Highlighting these altimeter-based success stories can serve to further promote the widespread adoption of the planned Surface Water and Ocean Topography (SWOT) mission scheduled for launch in 2022. SWOT has a wide-swath altimetry instrument based on interferometry with an on-board nadir altimeter. Knowledge of the breadth of utility of altimeter observations can support the scientific and applied science communities in tracking information about the applications they enable. This can help to maximize the societal value of current and planned suite of altimeters, as well as of future missions with expanded capabilities, such as SWOT.