The measurement and model construction of complex permittivity of corn leaves at the main frequency points of L/S/C/X-band

The complex permittivity of target has a crucial influence on its microwave radiation characteristics. In the quantitative research of microwave remote sensing, the study of the dielectric properties of vegetation to establish the relationship between its specific physical parameters and complex permittivity is the basic work in this field. In this study, corn leaves samples of different types and heights were collected at the city of Zhangye which is the key study area of the Heihe watershed allied telemetry experimental research and also the largest breeding base of hybrid corn seeds in China. Then the vector network analyzer E8362B was used to measure the complex permittivity of these samples from 0.2 to 20 GHz by coaxial probe technique. Based on these measurements, an empirical model of corn leaves which describes the relationship between the gravimetric moisture and both the real part and imaginary part of complex permittivity at the main frequency points of L/S/C/X-band was established. Finally, the empirical model and the classical Debye-Cole model were compared and validated by the measured data collected from the Huailai county in Hebei province. The results show that the empirical model has higher accuracy and is more practical than the traditional Debye-Cole model.