A fractal model for the sea state bias in radar altimetry
نویسندگان
چکیده
The Kirchhoo approximation is used to determine the sea state bias in radar altimetry. A weakly nonlinear model of the sea waves is used to derive the joint moments of two diierent points separated by a distance ~ R; the bias moment is formulated, and found for power law spectra. The method provides a consistent analysis of the sea state bias and avoids the need to trun-cate the high frequency tail of power-law wave spectra. The model exhibits dependence of the \electromagnetic bias" on the radar frequency, an eeect observed in eld experiments.
منابع مشابه
Sensitivity Analysis of Brown Model Waveform in Radar Altimetry
In satellite altimetry (radar altimetry), the altimeter emits a pulse, with known power, to the earth surface and receives it back continuously to determine of the sea surface height. The time series of the mean returned power is recorded individually at satellite as the so-called waveform. Analytical model for the waveform is first introduced by Brown, which consists of six parameters: signif...
متن کاملCombined airborne laser and radar altimeter measurements over the Fram Strait in May 2002
Knowledge of sea ice thickness is critical for the prediction of future climate, and for assessing the significance of changes in thickness. Sea ice thickness can be calculated from radar or laser satellite altimetry measurements of freeboard. However, a lack of knowledge of snow depth introduces significant uncertainties into these calculations. This paper compares the first coincident airborn...
متن کاملA Conceptually Simple Modeling Approach for Jason-1 Sea State Bias Correction Based on 3 Parameters Exclusively Derived from Altimetric Information
A conceptually simple formulation is proposed for a new empirical sea state bias (SSB) model using information retrieved entirely from altimetric data. Nonparametric regression techniques are used, based on penalized smoothing splines adjusted to each predictor and then combined by a Generalized Additive Model. In addition to the significant wave height (SWH) and wind speed (U10), a mediator pa...
متن کاملAnalytical Model of the Electromagnetic Bias Using the Physical Optics Scattering Theory
The electromagnetic bias (EM) is a critical error term in sea surface height estimation from satellite radar altimetry. At present the EM bias models used in current altimetry missions are empirically based and globally-averaged functions of the altimetermeasured signi cant wave height and wind speed alone. Recent studies have shown that a reduction in the EM bias error variance can be achieved...
متن کاملInvestigation of Geostrophic and Ekman Surface Current Using Satellite Altimetry Observations and Surface Wind in Persian Gulf and Oman Sea
The rise of satellite altimetry is a revolution in the ocean sciences. Due to its global coverage and its high resolution, altimetry classically outperforms in situ water level measurement. Ekman and geostrophic currents are large parts of the ocean’s current, playing a vital role in global climate variations. According to the classic oceanography, Ekman and geostrophic currents can be calculat...
متن کامل