A soil moisture observation network approved by NASA as a core validation site for the SMAP mission is deployed in the region of Millbrook, NY. It includes an L band (1.45 GHz) dual polarization radiometer that is part of the CREST Microwave Observation Unit. The study site serves as a calibration/validation site for the NASA SMAP mission.

The land cover in the region at the kilometer scale is a composite of open field (40%) and forested (60%) terrains and a small urban fraction (the Village of Millbrook). The area is about twelve miles from the Hudson River and includes a few small water bodies (Tyrrel Lake and Dieterich Lake) about 5 miles from the site. The relief in the area is relatively gentle. Soil texture in the region tends to be sandy loam with the following representative percentages of Sand: 60% Silt: 34%, and Clay: 6%. It was also observed that the soil column had a significant amount of rock, specifically shale, with a rock fraction that can reach up to 50%.