2005 Annual Report 4d.Progress report. This report serves to document research conducted under a reimbursable agreement between the ARS Hydrology and Remote Sensing Laboratory and the University of California, Davis. Additional details of research can be found in the report for the parent project 1265-13610-026-00D entitled, "INTEGRATING REMOTE SENSING, CLIMATE AND HYDROLOGY FOR EVALUATING WATER, ENERGY AND CARBON CYCLES." ARS led the development of experimental plans to test algorithms for retrieval of vegetation water content from the NASA MODIS sensor. Data sets were collected as part of the successfully completed Soil Moisture Experiments 2004 and 2005 in Arizona, Mexico, and Iowa. These data are being analyzed and provided to public archives. Cooperators included NASA, Naval Research Laboratory, universities, and ARS locations. This project will provide a significant step in developing synergy between optical and microwave sensors.