Geophysical model functions for the sea state bias in satellite altimetry

• Main Authors: Glazman, R.E., Greysukh, A., Zlotnicki, V.
• Format: Conference Proceeding
• Language: English
• Subjects: Altimetry; Amplitude modulation; Polynomials; Propulsion; Pulse shaping methods; Satellites; Sea level; Sea surface; Surface waves; Wind speed
• DOI: 10.1109/IGARSS.1993.322446

The sea state bias in altimeter measurements of sea surface height have been investigated by many authors, resulting in several proposed algorithms of the form SSB=/spl epsi/H where H is the significant wave height (SWH) and /spl epsi/ is a non-dimensional function of wind and wave parameters. All known algorithms are presently rated. The most popular, linear model of the form /spl epsi/=a/sub 0/+a/sub 1/U is shown to yield an improvement over the simplest algorithm with a constant /spl epsi/. A three-parameter form /spl epsi/=a/sub 0/+a/sub 1/U+a/sub 2/H produces even better results. However, the accuracy of the polynomial models is below that obtained with a two-parameter, physically-based model relating /spl epsi/ to the pseudo-wave-age /spl xi/: /spl epsi/=M/spl xisup -m/. The /spl xi/ is estimated using altimeter wind U and SWH: /spl xispl ap/A(gH/U)/sup V/ where A and v are constants. By analyzing the performance of different models we conclude that further progress can hardly be achieved by raising the degree of the polynomial for /spl epsi/(U,H). Physically-based approaches employing a small number of adjustable parameters and theoretically justified non-dimensional combinations of external wind and wave factors appear to be more promising.< >