Capability of Rice Mapping Using Hybrid Polarimetric SAR Data

The objectives of this paper are to investigate the capability of hybrid polarimetric synthetic aperture radar (SAR) data for rice mapping and to explore the relationships between the hybrid polarimetric information and rice biophysical parameters. The linear polarization ratio (μ
_L
) is analyzed on the basis of reflection symmetry and simulated data, and has been demonstrated to behave similarly to the HH/VV polarization ratio, which has been widely used in rice and wheat mapping. The degree of linear polarization (P
_L
) shows great potential in rice monitoring as well. In addition, a modified entropy-alpha decomposition method for hybrid polarimetric SAR is proposed to analyze the temporal scattering behaviors of rice in different growth stages. The degree of polarization (m), μ
_L
and P
_L
are shown to be able to reflect the growth status of rice to a certain extent, and their empirical models are explored. Time-series images acquired by Radarsat-2 at C-band and in situ data, such as the fresh biomass, dry biomass, height, and days after transplantation (DAT), are used to demonstrate the analytical method and the foresaid conclusions.