Soil moisture is a small but very active part of the hydrologic cycle. Recently many studies and reviews have been conducted on its impacts on climate change and short-term forecasting. Satellites could be used as a means for monitoring global soil moisture evolution. In November, 2009, the European Space Agency launched the first satellite dedicated to measuring soil moisture: Soil Moisture Ocean Salinity (SMOS). NASA is planning on launching its own satellite that will incorporate both a passive sensor (like SMOS) and an active sensor in hope of increasing the spatial resolution of the measurements. From September 23, 2008 (DOY266) through September 25, 2008 (DOY268), an aircraft equiped with both a passive and active sensor (PALS) flew over the Iowa Validation Site (IVS) making measurements of the soil moisture through a soybean canopy.