Early ground-reference calibration results for Landsat 7 ETM+ using small test sites

Recent results of the vicarious calibration of the Landsat-7 ETM+ sensor are presented based on the reflectance-based vicarious method using results from a smaller test site local to the University of Arizona area. This test site is not as bright, nor as spatially-uniform and as large as typical sites. However, the proximity of the site allows for more frequent calibrations and hopefully a better understanding of the calibration as a function of time. The selection of the test site, its properties, and example results of calibrations at this site are presented. The results from seven dates are presented and show that the ETM+ sensor has been stable to better than 5% since launch. The results from these seven dates have larger variability than those from the large test sites, but agree for the most part to better than 5% with the large test sites.