Integrated Time Domain Reflectometers with Sophisticated Waveform Digitizing and Analysis.

Soil Moisture Sensors based on waveform propagation time measurements overcome the overestimation of permittivity inherent in sensors based on Gauss’ Law.  New TDR sensors with integrated step function generators, waveform digitizers and precision time base facilities have been created and tested to show stable permittivity derivations in the presence of widely varying soil EC conditions.  Step function rise times in the 100ps range provide broad spectral content in waveforms digitized with 5ps resolution.