Statistical characterization of remotely sensed soil moisture images

Using ESTAR (Electronically Scanned Thinned Array Radiometer) passive microwave remotely sensed soil moisture data from the Washita 92 experiment, we examine the appropriateness of several probability density functions as a candidate for soil moisture distribution. Although the normal distribution is found to approximate the data well, it is shown that such a distribution cannot capture the inherent spatial structure of soil moisture. We confirm the recent finding that the variance of soil moisture images follows a power law decay and show that such a scaling is valid over a wider range of scales than previously reported. We also relate the scaling exponent of the variance to highly correlated cluster structure: in soil moisture images. Our analysis of scaling for higher-order moments suggests that soil moisture images may not be simple scaling.