Large area mapping of soil moisture using passive microwave radiometry in the Washita´92 experiment

Washita´92 was a large scale study of remote sensing and hydrology conducted over the Little Washita Watershed in southwest Oklahoma. Data collection during the experiment included passive microwave observations using an L-band electronically steered thinned array radiometer (ESTAR) and surface soil moisture observations. The watershed was saturated at the outset of the study, ESTAR data were processed to produce brightness temperature maps. These data exhibited significant spatial and temporal patterns. Spatial patterns were associated with soil textures and temporal patterns with drainage and evaporative processes. Spatial averaging was used to study scaling of data interpretation algorithms. Results of these studies were consistent with previous studies and showed that a strong relationship is retained at these scales