| Zusammenfassung |
The protection of the public against the harmful effects of ionizing radiation and radioactive contaminations caused by nuclear or other accidents is of major importance and may affect thousands of people. Following a radiological incident, radiation protection and other authorities need quick and credible information on affected areas. Large-scale contamination requires radiation measurement methods and tools able to quantify the risks in a timely manner. The unmanned airborne gamma spectrometry method brings together the benefits of a vast area coverage by an aircraft system, the mature spectrometric techniques for nuclide identification, and the safety of an operator staying out of the affected area.
This thesis investigates the metrological and technical challenges of implementing the airborne gamma spectrometry method using unmanned aircraft systems. For this purpose, a spectrometer-based dosimetric system was designed and implemented on a commercial drone. The system is built around a 1.5”CeBr3 scintillation detector, incorporates necessary telemetry instruments, and can be attached as a payload to a drone. During the flight, the system measures and transmits the radiation and telemetry data to the ground station where geo-tagged spectra are processed. The software package with the graphical interface has been developed to process the aerial data and supply an operator with such information as a dose rate map, spectrum history, flight altitude, temperature, and more.
This work describes the steps of the unmanned airborne radiation monitoring system characterization and presents the results of several measurement campaigns conducted within the EMPIR project ”Preparedness”. These campaigns covered the major radiological surveillance tasks, including dose rate mapping, measuring concentrations of ground-deposited radionuclides,
and the search and localization of a point-like radiation source. The conducted flight exercises demonstrated the good performance of the developed radiation monitoring system and its readiness to carry out routine and emergency aerial surveys.
The thesis builds upon the vast background of aerial gamma spectrometry techniques established by manned aircraft surveys since the early 1950s. The author introduces new techniques of the temperature stabilization of radiation spectra and the traceable spectrum-to-dose conversion that enhance the quality of the aerial system data output. The author has gained a profound experience in the subject through building, programming, calibrating, and operating the aerial system, including the piloting itself. Alongside the novel methods applied to the characterization and data analysis of the airborne radiation detector, this thesis provides feedback on the development and operation of an unmanned airborne radiation monitoring system. |
