Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: July 5, 2010
Publication Date: N/A
Technical Abstract: Validation is an important but particularly challenging task for passive microwave remote sensing of soil moisture from Earth orbit. The key issue is spatial scale; conventional measurements of soil moisture are made at a point whereas satellite sensors provide an integrated area/volume value for a much larger spatial extent. For microwave remote sensing from space we must consider the one to forty km scale, which presents challenges. Another important aspect of a successful validation for a global product is diverse conditions. These issues are common to SMOS and most other passive microwave sensors. In this stage of our studies we are focusing on the use of a set of dense in situ soil moisture observing networks distributed across the US as the primary resource to validate SMOS soil moisture, each of which approximate the size of a SMOS footprint. These sites have been calibrated and verified through field campaigns and applied to validating other satellite products. Although these dense sites provide diverse conditions, we are also enhancing our analysis by using data from a sparse Soil Climate Analysis Network (SCAN) distributed throughout the US. In this study, data from several months of SMOS observations are compared to the in situ resources.