MS-1200 sub onderwater gamma-ray spectrometer

Medusa’s gamma spectrometers are used worldwide to map soil and sediments. Due to the rapidly growing demand for sediment mapping surveys, Medusa Radiometrics invests in making the underwater gamma-ray spectrometers more manageable and more efficient. The sensor will be made autonomous, and we will develop technology to allow the sensor to communicate wirelessly with the vessel. The European Regional Development Fund (ERDF) funds the research.

Our ambition

At Medusa Radiometrics we work continuously to improve the applicability of our sensors. Our ambition is to make gamma-ray sensors used for mapping soil and sediment composition more efficient, more accurate and easier to operate.

Underwater mapping of sediments

The underwater gamma-ray spectrometer is used to measure the composition and contamination of sediments. The sensor is towed behind a vessel, slides over the sediment and continuously measures changes in composition of sediment. The current system uses the towline for data communication. However, this set-up is prone to errors and requires special cables. To make the application of the sensor more common, we are developing technology to allow the sensor to communicate wirelessly.

mapping with Medusa

Why use only point samples, i you can have a complete map of the composition of sediments?

Technical development

In the project we will make the sensor autonomous and we develop technology to allow the sensor to communicate wirelessly with the ship. This will be done by using acoustic modems. These modems are speakers/microphones that can be used underwater to transmit data via sound waves. Normal wireless connections such as WiFi and Bluetooth will not work underwater because they are damped by the water, making these acoustic modems the only option for wireless underwater communication.

The challenge is that the bandwidth (the amount of data that can be sent per second) of those modems is a factor of 10,000 lower than our current system needs to function.

We will therefore make the sensor much more “independent”. For this we will bring all data-acquisition hardware, which is now on board the vessel, to the sensor so that the system requires much less interaction with the operator. In addition, we will expand the system with an internal battery.

European support

The project is supported with funding from the European Regional Development Fund (ERDF) from the European Union with SNN as the implementing agency.