Dielectric constant determination using ground-penetrating radar reflection coefficients

Ž . A method to determine ground-penetrating radar GPR velocities, which utilize Brewster angles, is presented. The method determines the relative dielectric constant ratio at interface boundaries where the radar wave is traveling from a low-velocity to a high-velocity medium. Using Brewster angle analysis is currently the only means to determine the velocity of the medium below the deepest detectable reflector. Data are presented for water-saturated clean sand with a known velocity of 0.52 mrns, which overlays a sandy silt with a known velocity of 0.13 mrns. Brewster angle analysis of a Ž . common midpoint CMP survey gives a relative dielectric constant ratio of 33r4.77. The Brewster angle relative dielectric constant ratio is in good agreement with the relative dielectric constant ratio calculated from the known velocities. q 2000 Elsevier Science B.V. All rights reserved.