Geoscience Reference
In-Depth Information
24.6 ConClUSIonS
The GPR surface reflectivity method can be used to measure soil water content subject to the limita-
tions imposed by scattering and stratification of water content. The effective sampling depth can be
increased and the scattering effects reduced by using a GPR with a lower center frequency. Elevat-
ing the antenna reduces the water content variability related to scattering, but the measured values
will be less than for a surface without scattering effects. The simplistic interpretation model used
for estimating water content may be enhanced to accommodate scattering and stratification effects.
At this time, robust and practical processes to do this do not exist and are the subject of further
research.
RefeRenCeS
Chanzy, A., Tarussov, A., Judge, A., and Bonn, F., Soil water content determination using a digital ground-
penetrating radar,
Soil Sci. Soc. Am.
J.
, 60, 1318, 1996.
Davis, J.L. and Annan, A.P., Ground penetrating radar to measure soil water content, in
Methods of Soil
Analysis: Physical Properties
, 5, Dane J.H., and Topp G.C., Eds., Soil Science Society of America Book
Series, 446, 2002, chap. 3.1.3.5.
Giannopoulos, A., The investigation of transmission-line matrix and finite-difference time domain method for
the forward problem of ground penetrating radar. D. Phil. thesis, Department of Electronics, University
of York, UK, 1997.
Huisman, J.A., Hubbard, S.S., Redman, J.D., and Annan, A.P., Measuring soil water content with ground
penetrating radar: A review,
Vadose Zone J.
, 2, 476, 2003.
Redman, J.D., Davis, J.L., Galagedara, L.W., and Parkin, G.W., Field studies of GPR air launched surface
reflectivity measurements of soil water content, in
Proc. of the 9th International Conference on Ground
Penetrating Radar
, Santa Barbara, California, 2002, 156.
Redman, J.D., Galagedara, L.W., and, Parkin, G.W., Measuring soil water content with the ground penetrat-
ing radar surface reflectivity method: Effects of spatial variability, Paper 032276, in
Proc. ASAE 2003
Annual International Meeting
, Las Vegas, NV, 2003.
Serbin, G. and Or, D., Near-surface soil water content measurements using horn antenna radar: Methodology
and overview,
Vadose Zone J.
, 2, 500, 2002.
Topp, G.C., Davis, J.L., and Annan, A.P., Electromagnetic determination of soil water content: Measurements
in coaxial transmission lines,
Water Resour. Res.
, 16, 3, 574, 1980.
