Product overview

How do our gamma-ray sensors work?

Medusa provides a variety of survey tools designed for effortless measurement of spatial soil variation. Our gamma-ray spectrometers, at the core of these tools, passively detect the natural radioactivity in the topsoil. They are incredibly user-friendly, making it easy for anyone to use.

On this page, you can explore the diverse range of sensor sizes provided by Medusa Radiometrics. Each sensor is tailored for a distinct application. For those interested in the underlying principles, an explanation of using gamma-ray spectrometers for soil information gathering is available at the page's end.

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mDOS & Gamman


Whether doing an airborne survey, locating a lost source with a UAV, or using our detector for a handheld survey for mapping the environment, you can count on using the same familiar interface. mDOS is developed for in-the-field usage. Optimized for real-time monitoring, ease of use and automating your survey workflow.


GammAn is our comprehensive post-processing software tailored specifically for analyzing measurement results obtained from our gamma-ray detection systems.

Both mDOS and Gamman have been developed with a focus on user-friendliness, ensuring that users of all skill levels can effortlessly navigate and leverage the full potential of our detection systems. Whether you are a seasoned expert or new to gamma-ray analysis, our software packages provide the tools you need for accurate measurements and meaningful data interpretation.

mDOS en Gamman

The soil is ticking

Every soil contains soil radionuclides like potassium (K-40), uranium (U-238), thorium (Th-232), and sometimes cesium (Cs-137). The Medusa sensor can measure the signals emitted by these radionuclides. With our sensor, even the smallest variations in radionuclide concentrations within the soil can be detected, offering valuable insights into the soil's composition.

The fingerprint of the soil

Our sensors provide accurate insights into soil composition and a wide range of other soil parameters. In fact, the radionuclide signal is so distinctive that it is often referred to as the soil's fingerprint. Our sensors are used to measure soil composition and diverse soil properties including soil texture, minerals, and soil pollutants like heavy metals.

Size matters

Medusa has developed a variety of sensors designed for specific applications. Although all sensors share the same technology, operating system, robust electronics, and easy-to-use interface, the difference lies in their measurement efficiency. Larger sensors offer enhanced efficiency, enabling faster survey speeds and larger survey heights.

Finding the right sensor for the job is an intricate interplay between the accuracy needed on one hand and parameters such as the working speed, measurement height, and available payload on the other hand. For instance, when using drones, the available payload will restrict the maximum detector weight.