Abstract's details
Propagating uncertainties and error correlation structures through retracking and sea state bias correction
Event: 2022 Ocean Surface Topography Science Team Meeting
Session: Quantifying Errors and Uncertainties in Altimetry data
Presentation type: Poster
What is the uncertainty budget in deriving Global Mean Sea Level (GMSL) from satellite altimetry? This is one of the questions to be addressed within the framework of the ESA-funded project Assessment Sea Level rise Stability Uncertainty, ASeLSU. ASeLSU is approaching this question in a metrological manner which entails a full breakdown of all sources of uncertainties arising from the altimeter and assessment of error correlation structures to quantify the uncertainty budget.
From acquiring the radar backscatter to forming a waveform and estimating the GMSL, many processing steps are involved, which makes the uncertainty analysis intricate. This is especially true considering that components such as the altimetric range and sea state bias correction are not derived independently. Four primary parameters – epoch, sigma-0, significant wave-height, and mis-pointing angle – are derived from the most common retracking used MLE4 (Amarouche et al., 2004). Two of these parameters, sigma-0 and significant wave-height, are used to estimate the wind speed, which in turn is used with significant wave-height (again) to determine the sea state bias correction.
In this study, we performed simulations using simplified retracker algorithms to understand the extent of possible error correlations between the different quantities derived from retracking, and to propagate those through to sea state bias and the ionosphere correction.
Amarouche et al., 2004: https://doi.org/10.1080/01490410490465210
Back to the list of abstractFrom acquiring the radar backscatter to forming a waveform and estimating the GMSL, many processing steps are involved, which makes the uncertainty analysis intricate. This is especially true considering that components such as the altimetric range and sea state bias correction are not derived independently. Four primary parameters – epoch, sigma-0, significant wave-height, and mis-pointing angle – are derived from the most common retracking used MLE4 (Amarouche et al., 2004). Two of these parameters, sigma-0 and significant wave-height, are used to estimate the wind speed, which in turn is used with significant wave-height (again) to determine the sea state bias correction.
In this study, we performed simulations using simplified retracker algorithms to understand the extent of possible error correlations between the different quantities derived from retracking, and to propagate those through to sea state bias and the ionosphere correction.
Amarouche et al., 2004: https://doi.org/10.1080/01490410490465210