An Empirical Model for Backscattering Coefficients of Vegetation Fields at 5.4 GHz

A new, simple empirical model for microwave backscattering from vegetation fields at 5.4 GHz is proposed in this paper. First, a modified radiative transfer model (RTM) is used to generate a database of multi-polarized backscattering coefficients of various vegetation fields at 5.4 GHz with wide ranges of vegetation biomasses and soil moistures. Second, we propose a functional form of an empirical model that is a simplified water cloud model (VVCM) after closely examining the behaviors of the well-known WCM based on an extensive database that includes the modified RTM outputs, scatterometer measurements, SAR datasets, and in situ measured ground-truth data for various vegetation fields. Finally, the unknown constant parameters of the empirical model are determined for each soil moisture condition based on the extensive database. The new empirical model is verified with the database itself, and also with independent Sentinel-1 synthetic aperture radar (SAR) data and in situ measured ground-truth data.

Automated summary

A new empirical model for microwave backscattering from vegetation fields at 5.4 GHz is proposed in this paper. The model was developed based on a modified radiative transfer model and a database of multi-polarized backscattering coefficients. The model was validated using the database itself, as well as independent Sentinel-1 SAR data and in situ measured ground-truth data.