Notice to Data Users: The documentation for this data set was provided solely by the Principal Investigator(s) and was not further developed, thoroughly reviewed, or edited by NSIDC. Thus, support for this data set may be limited. This data set combines data for several parameters measured as part of the Soil Moisture Experiment 2004 (SMEX04). Field measurements were obtained from 2 August ... through 26 August 2004 with a variety sensors, such as probes and pyrometers, within the regional study area of Arizona, USA. The parameters include gravimetric soil moisture, volumetric soil moisture, soil and surface temperature, and bulk density. Summary files containing field averages are also provided for simplicity. The total volume of this data set is approximately 1 MB. Data are provided in ASCII text files and are available via FTP. These data were collected as part of a validation study for the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E). AMSR-E is a mission instrument launched aboard NASA's Aqua Satellite on 04 May 2002. AMSR-E validation studies linked to SMEX are designed to evaluate the accuracy of AMSR-E soil moisture data. Specific validation objectives include assessing and refining soil moisture algorithm performance; verifying soil moisture estimation accuracy; investigating the effects of vegetation, surface temperature, topography, and soil texture on soil moisture accuracy; and determining the regions that are useful for AMSR-E soil moisture measurements.