Kansas Geological Survey, Current Research in Earth Sciences, Bulletin 247, part 1
Modeling Dielectric-constant Values of Geologic Materials: An Aid to Ground-penetrating Radar Data Collection and Interpretation--Fig. 11

Fig. 11. Calculated reflection coefficients for dry and water-saturated quartzose ( = 4.5) models plotted against porosity differences ranging from 0% to 50%. The shaded area indicates power reflectivity values of less than 0.01, a conservative estimate of the threshold at which background noise may preclude recording of reflection information (i.e., SNR 1; Annan, 1996).