Sea State Bias in Radar Altimetry Revisited

Abstract

Sea state bias (SSB) is calculated anew for each radar altimeter. The input data are sea surface height (h) differences, separated in time by at most one repeat cycle, or the difference between measured h and a time-mean sea surface, an approach called here “differences from the mean” (DFM). In order to release data to users soon, early estimates of SSB are computed from short time series. This work has three objectives: 1) show that the DFM approach introduces spurious values in the estimated SSB, 2) quantify the SSB error caused by short time series, and 3) estimate SSB for OSTM.

Keywords:

• Jason-1
• OSTM
• sea state bias
• mean sea surface

Acknowledgements

We are grateful to Dimitris Menemenlis and the ECCO2 Team for the ECCO2 output, Akiko Hayashi for the Jason data gridded alongtrack, and Remko Scharroo for the very useful RADS database. Jason-1 GDR data were also obtained from PO.DAAC. This work was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration, and sponsored by NASA's Physical Oceanography Program (VZ) and the Earth Observing System's Data and Information System (JH).