For over three decades, satellite radars have used the Amazon tropical rain forest as a stable homogeneous and isotropic scattering target for calibration. This thesis extends previous work to consider the use of the Amazon as a blackbody target for passive microwave inter-satellite calibration. The characterization of a natural target for radiometric calibration is a formidable task due to the difficulty in obtaining an absolute brightness temperature standard. Previously, multi-frequency microwave brightness temperatures measured by the Tropical Rainfall Measuring Mission Microwave Imager (TMI) were used to provide multi-year observations in local time windows. Our approach differs in that we will combine the land surface measurements of the Moderate Resolution Imaging Spectroradiometer MODIS (on AQUA and TERRA Earth Observing Satellites) with the variable time of day multi-frequency microwave brightness temperatures measured by TMI. There are two principal goals of this research, namely; (1) to characterize the mean multi-frequency polarized (V-pol & H-pol) brightness temperature over the entire Amazon rain forest region at a 0.25 deg spatial resolution in one-hour local time windows, and (2) to determine the corresponding microwave emissivity for this entire region using the land surface temperature data from the MODIS
