• 2023-07-18

A new soil moisture sensor

Every soil naturally contains radionuclides that can be identified using a gamma-ray sensor. Additionally, the soil's moisture content fluctuates over time due to precipitation and evaporation. As gamma-rays are affected by moisture, alterations in the soil's moisture level directly impact the gamma-ray flux emitted by the soil. This principle simplifies to a direct correlation: the higher the moisture content in the soil, the lower the gamma-ray flux. What makes this even more intriguing is that this relationship can be harnessed to monitor soil moisture accurately, accomplished by utilizing a gamma-ray spectrometer.

Ordinarily, the impact of soil moisture is considered insignificant and often disregarded. However, through meticulous and extended measurements, it becomes feasible to deduce the moisture levels within the soil. To serve this purpose, Medusa has innovated the gamma Soil Moisture Sensor (gSMS-100). This specialized sensor is designed to conduct highly accurate, long-term gamma-ray flux measurements, enabling precise assessment of soil moisture content.

Read more about the development

gSMS schematic
UAV soil moisture measurement

In a recent study, the gSMS was deployed in an agricultural field alongside a conventional point moisture sensor and a rain gauge. Over a span of six months, the moisture readings from both sensors were compared. The measurements derived from the gamma-ray fluxes strongly correlate with precipitation events and estimated soil moisture content. One significant advantage of this novel moisture sensor is its ability to gather data from a substantial volume of soil. Unlike traditional point-based sensors, which provide localized readings, the gSMS offers a more accurate representation of the average moisture concentration over a wider area. This feature enhances its reliability and applicability in agricultural and environmental monitoring.

Read more in Chapter 6

Currently, several research institutes are using the new technology to asses the moisture in the area for agricultural, forestry, and environmental applications.