User Guides - Sentinel-3 Altimetry - Geophysical Measurements - Sentinel Online
The main geophysical parameters to be measured by the SENTINEL-3 topography mission are:
- Surface Height (SSH)
- Significant Wave Height (SWH)
- Wind speed over ocean surface.
These parameters are retrieved from the physical characteristics of the altimeter waveforms received by the SRAL instrument.
Figure 1: Physical Characteristics of the Altimetry Waveforms (Credit: isardSAT)
- Epoch: this is related to the range. SSH is computed from it.
- P: power of the useful signal. This power, with respect to the emitted power, gives the backscatter coefficient, sigma0. Sigma0 (together with the SWH) is used to estimate wind speed.
- Leading edge slope: this can be related to the Significant Wave Height (SWH).
- Trailing edge slope: this is linked to antenna mis-pointing and Significant Wave Height (SWH).
|Range||1.25 cm||1.67 cm||2.53 cm|
|SWH||9.7 cm||11.4 cm||16.2 cm|
|Wind Speed||16 cm.s-1||21 cm.s-1||17 cm.s-1|
|NRT||1.25 cm||1.67 cm||2.53 cm|