Quality assurance measures in airborne gamma spectrometry

Since 1993, the task "airborne radiation detection" has been carried out in close cooperation between the Federal Office for Radiation Protection (BfS) and the German Federal Border Police (Federal Police (BPOL) since 2005).

Measurement campaigns

In order to ensure operational readiness in airborne gamma spectrometry at any time, national or international measurement campaigns are carried out every year.

Areas in Germany where airborne gamma spectrometry measurement exercises have been conducted since 1993

The cooperation between the BfS and the BPOL is trained within national measurement campaigns. To that end, the BfS and the BPOL perform measurement flights in areas with different terrain structures and significantly increased levels of radiation.

The exercises focus on

• the large-scale mapping of natural radionuclides,
• the optimisation of the measurement and evaluation software as well as
• the timely on-site evaluation of the recorded measurement data and the transmission of the measurement results to an evaluation centre.

Research projects

The main field of application of airborne gamma spectrometry is the rapid and large-scale determination of ground-deposited radioactive material in the context of emergency preparedness, for example after a nuclear accident. In order to keep the scientific quality of airborne gamma spectrometry at the current level, the BfS initiates research projects among other things.

In 2011, the BfS launched the research project "Further development of the airborne gamma spectrometry measurement systems of the Federal Office for Radiation Protection (BfS) and adaptation of the measurement and evaluation methods to the requirements of emergency preparedness (2011-2014)" that was conducted by the independent technical service corporation TÜV SÜD.

In the scope of the research project the following methods were developed:

• modelling of photon flux densities taking into account complex boundary conditions;
• angle and fuel level dependent calibration of the measurement system built into the helicopter;
• a method for extending the operational capability of airborne gamma spectrometry (for example when air contaminations are present).