These pages contain whitepapers and technology documentation on the Medusa Systems and Software.

Publications and whitepapers on radiometrics

ApplicationTitleTopicYearDownload paper
Drone-borneJournal of Environmental Radioactivity articleOptimizing gamma-ray spectrometers for UAV-borne surveys with geophysical applications2021
Drone-borneJournal of Environmental Radioactivity articleFootprint and height corrections for UAV-borne gamma-ray spectrometry studies2021
Drone-borneFast Times articleDrone-borne gamma-ray spectrometry – a dream come true!2020

Drone-borneFirst Break article

Towards drone-borne gammaray mapping of soils


Drone-borneEAGE NSE-2018 invited talkA drone as platform for airborne gamma-ray surveys to characterize soil and monitor contaminations2018

Drone-borneEAGE NSE-2018 extended abstractDrone-borne surveying with spectrometers - case studies2018

AirborneMedusa MapsPDF of a powerpoint containing sample maps taken with our MS-4000.2015
AirborneTowards lightweight airborne
gammaray spectroscopy

Whitepaper on the first "big-time" airborne survey done with a MS-4000 4L crystal system. Survey done for URAMAD (Madagaskar), in total about 80,000 line kms were surveyed yielding over 40 confirmed 238U anomalies

AirborneBenchmarking a small
footprint detector system
A comparison between airborne data taken by traditional 4x4L systems and a MS-4000. Collaboration between BGR (Germany), Terraquest Ltd (Canada) and Medusa Sensing BV2011
AirborneSkyTEM Multi Geophysical Airborne SurveysTechnology paper on the SkyTEM integration of MS-4000 on the SkyTEM frame2013
AirborneEAGLEPresentation of first-ever microlight AGRS survey! The test was done together with the South African Counsil for Geoscience under supervision of dr. Edgar Stettler, dr Henk Coetzee and prof. dr. Rob de meijer. On the side you find both the presentation and the report on this survey.1997

In situ radiometric mapping as a proxy of sediment contamination: Assessment of the underlying geochemical and -physical principles

Paper describing the geochemical principles that make the sediment contamination can be mapped by using a gamma-ray spectrometer.

Mapping Sediment Contamination with a Gamma-Ray Spectrometer, Underwater and on Land

Environmental contamination due to human activity is recognized as one of the modern dangers of our industrial advancements. At present, there are no means for the passive, in-situ mapping of contaminants in aquatic and non-aquatic sediments. As a result, a proper risk assessment of sediment contaminant levels is often overtly expensive or lacks proper data.

Our method addresses the main problems associated with the current approach. We propose a method that provide rapid, spatially detailed data on contaminant distributions and concentrations in sediments by using a gamma-ray spectrometer. A gamma-ray spectrometer can be used for mapping aquatic sediments (by using a vessel as platform) and non-aquatic sediments as floodplains by using a quad-bike or drone as platform for the sensors.

Data fusion for inland

Paper on the use of our MS-700 gamma-ray multisensor system applied to environmental mapping of Dutch
canals suffering from heavy metal pollution Paper published in Hydro, nov 2008


An Underwater Gamma Spectrometer as Tool for  Ecological Assessment

In recent years, laws ands regulations in the field of ecology became more strict due to public pressure. Therefore, the discharge of fines during dredging and land reclamation works and its impact on seafloor habitats is an important aspect in environmental impact assessments.

We describe an approach in which an underwater gamma spectrometer can be used to quantitatively map the concentration of fines in sediments. With this approach, the natural variation of fines and thereby the buffering capacity of the seafloor can be monitored and the natural dynamics due to re-suspension and large-scale sediment transport patterns can be quantified. The information derived from the geophysical measurements give the opportunity to measure the effects of human induced projects at sea.

Paper presented at the EAGE near surface conference in Barcelona, 2016

Carborne /
Zinc slags in roads

Paper describes a radiometry-based method to map zinc slags that are used in roads in a large area in The Netherlands and in Belgium. The slags leach heavy metals and therefore needed to be found back and

Result of a collaboration with Fugro


AgriculturalFrom fielddata to mapsPresentation at Pedometrics 2017 (Wageningen) on first results of our Drone borne gammaray detector2017


Soil sensing and yield improvement
on marginal soils in Spain

Soil mapping provides information on the variation in physical characteristics of agricultural fields. For the
EU Life+ project ‘Crops for better soil’ we developed a soil mapping tool consisting of a MS-1200
based gamma spectrometer and GPR on a 4x4car, which was able to map large and widespread areas fast and effectively.

AgriculturalGamma Ray Sensor for
Topsoil Mapping
Reviewed paper on the use of radiometrics as a tool for soil mapping.2010
AgriculturalSoil parameters measured by GeophysicsTable showing the type of parameters that can be inferred from gammaray survey data2010
AgriculturalCrops for better soil

EU project CROPS FOR BETTER SOIL Presentation (a European project in Spain where the system is applied for soil mapping).

Multi Sensor Soil Sensing Tool for Farmland in Spain 

Medusa developed an efficient and effective soil sensing system (gamma-ray and GPR) on a 4x4 car to be able to measure >100 fields, 300 ha throughout the north of Spain in 3 weeks. The sensing data was combined with open data (DEM, geology) and soil sampling results (by UPM) to acquire information about soil texture, soil organic matter, tillage layer depth, compaction, altitude, slope, nutrients. This provided a good understanding of the soils and is a powerful communication tool for farmers and agronomists. 

This paper was presented at the EAGE near surface conference in Barcelona, 2016


BoreholeTowards better borehole logsA paper presented at the SAGA 2015 conference held in South Africa, September '15. The paper discusses a new approach to correcting spectral gamma data taken in boreholes. It is our aim to arrive at a worldwide interconnected series of calibration pits for spectral gamma borehole tools allowing proper inter comparison of data.2015

Towards a global network of gamma-ray detector

calibration facilities

Gamma-ray logging tools are applied worldwide. At various locations, calibration facilities are used to calibrate these gamma-ray logging systems. Several attempts have been made to cross-correlate well known calibration pits, but this cross-correlation does not include calibration facilities in Europe or private company calibration facilities. Our aim is to set-up a framework that gives the possibility to interlink all calibration facilities worldwide by using ‘tools of opportunity’–tools that have been calibrated in different calibration facilities, whether this usage was on a coordinated basis or by coincidence.

>> Paper published in Exploration Geophysics. Check

BoreholeTech preview SupertoolA preview paper on a novel borehole tool we developed. The tool has a CeBr3 crystal connected to a small footprint multichannel analyzer board. the paper shows the specs of the tool that exceed industry standard tools by at least a factor of 2!2015
BoreholeWhen every count countsPaper on how to get the most out of your spectra gamma log data. Published in the Wireline magazine of Marcus Chatfield2014
BoreholeRadon in boreholesCase study of the power of full spectrum analysis to find the cause for apparent high 238U count rates in
a borehole measurement. Radon is seen to be the cause

3rd party papers

TitleTopicYearDownload paper
UMC financial statement

Confirmation by UMC Energy PLC of the value of the MS-4000 data taken in Madagaskar
in 2007 and 2008.

Hunt for heavy metalFugro publication on joint Fugro-Medusa zinc slag project in De Kempen area. Published in
the Fugro internal newspaper Cross Section
Bakkie of the SkiesSouthafrican publication on a gyrocopter-based installation of a MS-4000 system2012
Archeologisch gebruikslandschap
slim en snel in kaart
(Dutch) paper on the use of gammaray scanning of topsoil for archeological purposes.2015
Veranderingen in een 17de eeuws grafveld op Spitsbergen door dooiende permafrost(Dutch) paper on mapping the depth of permafrost at Svalbard with different geophysical methods. The MS-1000 was used for mapping purposes. 2019