Analysis and Surface Parameter Retrieval from Multitemporal Airborne and Satellite Data During AGRISAR 2006

Water and energy fluxes at the interface between the land surface and atmosphere are strongly depending on the surface soil moisture content which is highly variable in space and time. It has been shown in numerous studies that microwave remote sensing can provide spatially distributed patterns of surface soil moisture. In order to use remote sensing derived soil moisture information for practical applications as e.g. flood forecasting and water balance modeling in mesoscale areas, frequent large area coverage is a prerequisite. The present paper investigates the potential of using frequent microwave observations to retrieve information on surface soil moisture characteristics, as they will become available from the SENTINEL-1 mission. SAR data from the ESA AGRISAR 2006 campaign is used for that purpose. The paper first investigates the potential of using different models for the retrieval of surface soil moisture information using airborne data. An empirical parameter retrieval model is then applied for the retrieval as well as to ENVISAT ASAR satellite data to investigate the trade-off in spatial scale. The rms error of the retrieval results was found to be between 4 and 7 vol.%, which is consistent with previous findings.