The Electromagnetic 'Wave' in Sensing Soil Water Content
Location
Eccles Conference Center
Event Website
http://water.usu.edu/
Start Date
3-27-2006 3:30 PM
End Date
3-27-2006 3:45 PM
Description
Electromagnetic (EM) measurement techniques have proliferated to worldwide use for soil water content determination. The seminal work of Topp, Davis and Anan (1980) illuminated the accuracy and robustness of time domain reflectometry (TDR) for samplescale soil moisture determination. Ground penetrating radar evolved as a tool for geophysical surveys and has potential for high resolution characterization of the vadose zone. At an even larger scale, remotely sensed measurements of surface reflectance are employed to infer surface soil moisture. Common to all of these EM measurement methods is the determination of the porous medium dielectric (permittivity) that serves as the primary indicator of water content. An understanding of the primary and other secondary effects that potentially contribute to erroneous dielectric readings is important for research tied to water content measurements. There is potential for enhancing the information content of EM measurements using the frequency-dependence of permittivity. Limitations for applying EM techniques should be understood in order to facilitate measurements under attenuating conditions. Finally, there is a need for upscaling TDR-based water content determinations to the field- or watershed-scale for calibration and linking of GPR or remotely sensed measurements.
The Electromagnetic 'Wave' in Sensing Soil Water Content
Eccles Conference Center
Electromagnetic (EM) measurement techniques have proliferated to worldwide use for soil water content determination. The seminal work of Topp, Davis and Anan (1980) illuminated the accuracy and robustness of time domain reflectometry (TDR) for samplescale soil moisture determination. Ground penetrating radar evolved as a tool for geophysical surveys and has potential for high resolution characterization of the vadose zone. At an even larger scale, remotely sensed measurements of surface reflectance are employed to infer surface soil moisture. Common to all of these EM measurement methods is the determination of the porous medium dielectric (permittivity) that serves as the primary indicator of water content. An understanding of the primary and other secondary effects that potentially contribute to erroneous dielectric readings is important for research tied to water content measurements. There is potential for enhancing the information content of EM measurements using the frequency-dependence of permittivity. Limitations for applying EM techniques should be understood in order to facilitate measurements under attenuating conditions. Finally, there is a need for upscaling TDR-based water content determinations to the field- or watershed-scale for calibration and linking of GPR or remotely sensed measurements.
https://digitalcommons.usu.edu/runoff/2006/AllAbstracts/48