Exploitation of the full SAR-mode signal for different applications
Event: 2014 Ocean Surface Topography Science Team Meeting
Session: Instrument Processing: Measurement and retracking (SAR and LRM)
Presentation type: Type Oral
Contribution: PDF file
The SAR-mode altimeter carried on-board the ESA Cryosat-2 satellite has already demonstrated its ability to provide enhanced performances compared to the conventional mode over open ocean, with improved range precision and reduced along track spatial resolution (from 10km to 300m). This result has been achieved by analyzing the parameter estimates from multi-looked SAR power echoes (that are obtained by averaging beam waveforms in the stack along the azimuth direction). However the exploitation of the power distribution in delay does not permit to resolve or distinguish particular parameters that exhibit same impact on the multi-looked SAR echo but having totally different signatures in the stack (such as the along-track mispointing angle and the estimates amplitude). By analyzing the distribution of power across the looks in the stack, amount of relevant information may be found in open ocean (ocean surface roughness, slope of the surface, high reflectivity surface), but also in polar ocean, coastal zone and major hydrological river basins. This paper presents a method based on the use of two types of signal generated in SAR processing (results of the stack averaging in the azimuth and range directions) that aims at exploiting the full capabilities of the SAR-mode radar altimeter.