Sensitivity Analysis of Copolar Complex Coherence for Crop Monitoring At L-Band

Time series of polarimetric SAR images are usually employed for agricultural crop monitoring. Most methods exploit backscattering coefficients, radar vegetation indices (RVI), and outputs from target decompositions. This paper investigates the sensitivity of the co-polar complex coherence to the growth of three crop types (barley, corn, and canola) using L-band data from two airborne campaigns. The co-polar complex coherence is represented on the complex plane (unit circle) for interpretation. The experimental results from this paper reveal that the changes in the position of the co-polar complex coherence and the shape of complex coherence region are highly sensitive to specific growth stages of the examined crops. For a given crop type, changes in coherence can reflect variations in crop biophysical parameters, and inhomogeneities within the field. Furthermore, the trends in coherence variation throughout the given growth stages differ among crop types.