Modelling the radiometric response of a dynamic, 3D structural model of wheat in the optical and microwave domains

A dynamic 3D structural model of wheat is used to simulate growth stages of a wheat canopy. The 3D information regarding canopy structure output by this model is used to drive two models of canopy radiometric response, one in the optical and one in the microwave domain. The radiometric response of the canopy in the optical and microwave domains is simulated and the sensitivity of the canopy response to variation in the canopy structural and radiometric parameters is examined. The modelled canopy response is compared to field-measured hyperspectral reflectance in the optical, and airborne synthetic aperture radar (E-SAR) backscatter measurements in the microwave. The modelled signal is shown to agree in general with observations. It is demonstrated that the major growth development stages of the wheat canopy which impact the remote sensing signal in the optical and microwave domains can be modelled in this way. This method is shown to be suitable for exploring the impact of canopy structure on remotely sensed measurements.