Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: 10/20/2007
Publication Date: 12/9/2007
Citation: Jackson, T. 2007. Large scale field campaign contributions to soil moisture remote sensing [abstract]. EOS Transactions, American Geophysical Union, Fall Supplements. 88(52):H21J-01. Interpretive Summary:
Technical Abstract: Large-scale field experiments have been an essential component of soil moisture remote sensing for over two decades. They have provided test beds for both the technology and science necessary to develop and refine satellite mission concepts. The high degree of spatial variability of soil moisture and the relatively coarse resolution of satellite observations present significant challenges for scaling and the design of these field campaigns. Earlier experiments, in particular Washita’92, established the credibility of large scale application of microwave remote sensing. Of particular significance was the demonstration of synthetic aperture radiometry (now the core technology of the Soil Moisture Ocean Salinity, SMOS, mission), spatial mapping and consistent retrievals, and the temporal information content of repeat observations in deriving soil hydraulic properties. Basic concepts were expanded in both space and time in experiments such as SGP97 that attempted to integrate the soil moisture observations in the broader framework of land surface hydrology. These types of campaigns have expanded globally. Within the U.S. in recent years they have focused on two issues; establishing the foundations of a future active-passive soil moisture satellite mission and the development and validation of current satellite soil moisture algorithms. Experiments involving a range of spatial domains (point, field, region) and geographical domains have contributed to establishing scaling relationships for both measurements and processes. Future experiments must continue to address the needs of planned soil moisture missions such as SMOS and Aquarius. As the Soil Moisture Active Passive (SMAP) mission concept continues to develop, there will be an increasing need to test and refine algorithms and in the post-launch time frame, there will be a need for validation products. These needs must be integrated with broader science objectives (to the degree it is possible) in order to secure the required resources. Efforts should be made to find communality with other missions and other research programs.