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All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Geant4 Tutorial CD

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Johnson, T.↗
DOE OSTI2018

UAVs for Radiological Monitoring: Determining Ideal Operational Parameters From GEANT4 Simulations - 18025

Owing in no small part to the enormous advances in radiation detector technology (size, sensitivity and spectral-resolution), there has been an increased drive and requirement to accurately map both the spatial extent and magnitude of radiological contamination at the greatest possible spatial resolutions. To undertake this, a range of different methods have been devised and include the use of cars and human, but also planes (and more recently) unmanned aerial vehicles (UAVs). However, critical to the remote sensing using such UAVs in contrast to ground-based sensing, is (i) the selection of the ideal operational parameters to attain the best on-ground resolution in addition to, (ii) understanding the correct normalisation procedures and other influences on results that surveys at these reduced altitudes might present. Resulting from earlier works, through employing combined modelling and experimental data, the optimal height for a UAV survey using the more realistic 'area' radioactive source term (opposed to an infinitely-small 'point-source') is determined to be approximately 5 m - suitably maximizing cross detector counts. At greater altitudes than this, the influence of variations in neighboring topology / topography and nearby structures are observed to be negligible. However, at this and further-reduced altitudes (where optimal count-rates exists), small height-related variations are observed to result, and impact considerably on the complexity of the data normalisation. Whilst not occurring as a tool to entirely replace ground-based surveys, UAV systems are able to perform in challenging or dangerous environments, inadvisable or problematic to send humans. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗