A Modified Water-Cloud Model With Leaf Angle Parameters for Microwave Backscattering From Agricultural Fields

This paper presents the development of an accurate and simple scattering model for radar backscatters of agricultural fields. We modified the water-cloud model (WCM) by adding new parameters (the average and standard deviation of leaf angle distribution) to accurately estimate the backscattering coefficients with the angular effect of scattering particles in a vegetation canopy. A relatively accurate radiative transfer model (RTM) and field measurements were used in this modification. The accuracy of the RTM was verified with the C-band ground-based scatterometer data of a cornfield, the X-band synthetic aperture radar data and ground-based scatterometer data of a bean field, and the in situ measured ground-truth data of those fields. The newly modified WCM (MWCM) was also verified with the measurement data. It was found that the root-mean-square errors between the MWCM and the measurements were less than 1.5 dB for all backscatter data from the agricultural vegetation fields.