Basic study of water distribution measurement in soil using SLDV

We propose a method of monitoring and imaging of the water content in the rooting zone using a sound vibration and the scanning laser Doppler vibrometer (SLDV). There is an advantage that is possible to measure a wide area by using a sound vibration. From the experimental results, we can confirm that the speed of sound value becomes fast in the place which is near the position of the water distribution. Also, we can see that the difference of the propagation velocity distribution reflected the difference of the water distribution. We plan to measure when changing the depth of the water distribution position and the implication water ratio in the future.