430 
Field : F 
Configuration : CHI! 
s=0.84 cm (ks=0.94) 
1=4.94 cm (kl=5.54) 
1 EM: CHH (Phi =0°) 
I EM: CHH (Phi =90°) 
A CHH (Measured) Phi=0° 
A CHH (Measured) Flii=90 o 
Incidence Angle (deg) 
Field : F 
Configuration : CW 
s=0.84 cm (ks=0.94) 
1=4.94 cm (kl=5.54) 
1 EM: CW (Phi =0°) 
I EM: CW (Phi =90°) 
A CW (Measured) Phi=0° 
A CW (Measured) Phi =90° 
Incidence Angle (deg) 
figure 7 
6. CONCLUSION 
The results presented previously show that the comparison between simulation and radar measurements 
depend on the surface roughness, and frequency. 
Over rough surface, the variation of the radar measured backscattering coefficient with the incidence 
angle is reproduced by the model in both C and X band. 
Over smooth surface and in X band, there is a correlation between the slope of the measured 
backscattering coefficient and the simulation results. At C band, the variation of the backscattering 
coefficient with incidence angle is not any longer reproduced by simulation. 
This last remark suppose that at low frequency, the wave penetration depth could not be neglected and a 
volume wave diffusion become important in the interaction mechanism. 
References: 
[1] A.K Fung, K.S. Cben: Dependence of surface back scattering coefficient on roughness, frequency and 
polarisation states. 
InL J. Remote Sensing, Voi. 13, n° 9, 1663-1680. (1992) 
[2] [3] A.K Fung and G.W. Pan : A scattering model for perfectly conducting random surfaces. (I: model 
development, II: range validity). 
IEEE Transaction on Geoscience and Remote sensing, Voi 30, n° 4, July 1992 
[4] R.T Shin and Kong : Scattering of electromagnetic waves from a randomly perturbed quasi-periodic 
surface. J. App. Phys. 56 (1), July 1984. 
[5] M. Benallegue: Etude de la faisabilité de la mesure par radar de l'humidité et de la rugosité des sols. 
Thèse de Doctorat en Sciences, Université de Paris XI Orsay (18 octobre 1993).