Kw. Weiler et al., COMPARISON OF GROUND-PENETRATING RADAR AND TIME-DOMAIN REFLECTOMETRY AS SOIL-WATER SENSORS, Soil Science Society of America journal, 62(5), 1998, pp. 1237-1239
Robust and noninvasive techniques for in situ measurement of soil wate
r content are essential for monitoring and research of many hydrologic
processes. Although in situ measurement of soil water content by mean
s of a soil's electric and dielectric properties has been explored ext
ensively, the use of ground-penetrating radar (GPR) for this purpose i
s not well established. We compared the soil's dielectric constant as
measured by GPR and time domain reflectometry (TDR) and its relationsh
ip to water content determined independently in auger holes. We propos
e a calibration equation relating soil water to GPR-measured dielectri
c constants. The difference in calibration equations between GPR and T
DR was partially attributed to the difference in frequency ranges in w
hich TDR and GPR operate and the zero offset of the GPR.