This data set contains observations of atmospheric parameters from aerosol optical property measurements collected during the Soil Moisture Experiment 2004 (SMEX04) in Arizona, USA. Data were collected by the Aerosol Robotic Network (AERONET) program, a federation of ground-based remote sensing aerosol networks composed of automatic sun and sky scanning radiometers. A sun photometer was set up within the Arizona experimental site for the collection of aerosol optical properties throughout the course of the SMEX04 field campaign. Parameters include: spectral aerosol optical depths; precipitable water; sky radiance distributions and aerosol volume; and particle size distribution. Three levels of data are available: Level 1.0 (unscreened), Level 1.5 (cloud screened), and Level 2.0 (cloud-screened and quality-assured). Temporal coverage for the data spans 18 June 2004 to 16 November 2004. The volume of the data set is approximately 10 kilobytes for one day of observations, provided in comma-delimited ASCII text files.
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.