Airborne Gamma-Ray Spectroscopy for Modeling Cosmic Radiation and Effective Dose in the Lower Atmosphere

In this paper, we present the results of an ~5-h airborne gamma-ray survey carried out over the Tyrrhenian Sea in which the height range (77–3066) m has been investigated. Gamma-ray spectroscopy measurements have been performed using the AGRS_16L detector, a module of four 4L NaI(Tl) crystals. The experimental setup was mounted on the Radgyro, a prototype aircraft designed for multisensorial acquisitions in the field of proximal remote sensing. By acquiring high-statistics spectra over the sea (i.e., in the absence of signals having geological origin) and by spanning a wide spectrum of altitudes, it has been possible to split the measured count rate into a constant aircraft component and a cosmic component exponentially increasing with increasing height. The monitoring of the count rate having pure cosmic origin in the >3-MeV energy region allowed to infer the background count rates in the 40K, 214Bi, and 208Tl photopeaks, which need to be subtracted in processing airborne gamma-ray data in order to estimate the potassium, uranium, and thorium abundances in the ground. Moreover, a calibration procedure has been carried out by implementing the CARI-6P and Excel-based program for calculating atmospheric cosmic ray spectrum dosimetry tools, according to which the annual cosmic effective dose to human population has been linearly related to the measured cosmic count rates.

[1]  Marica Baldoncini,et al.  Exploring atmospheric radon with airborne gamma-ray spectroscopy , 2017, 1712.04797.

[2]  Mirko Reguzzoni,et al.  Accuracy of Flight Altitude Measured with Low-Cost GNSS, Radar and Barometer Sensors: Implications for Airborne Radiometric Surveys , 2017, Sensors.

[3]  Tatsuhiko Sato.  Evaluation of World Population-Weighted Effective Dose due to Cosmic Ray Exposure , 2016, Scientific Reports.

[4]  D. Beamish.  Enhancing the resolution of airborne gamma-ray data using horizontal gradients , 2016 .

[5]  A. Silva,et al.  Boolean and fuzzy methods for identifying lateritic regoliths in the Brazilian Amazon using gamma-ray spectrometric and topographic data , 2016 .

[6]  Xiaobin Tang,et al.  Efficiency calibration and minimum detectable activity concentration of a real-time UAV airborne sensor system with two gamma spectrometers. , 2016, Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine.

[7]  Mats Söderström,et al.  Adaptation of regional digital soil mapping for precision agriculture , 2016, Precision Agriculture.

[8]  R. Kleinschmidt,et al.  Terrestrial gamma radiation baseline mapping using ultra low density sampling methods. , 2016, Journal of environmental radioactivity.

[9]  Tatsuhiko Sato,et al.  Analytical Model for Estimating Terrestrial Cosmic Ray Fluxes Nearly Anytime and Anywhere in the World: Extension of PARMA/EXPACS , 2015, PloS one.

[10]  Peng Wang,et al.  Spectrum correction algorithm for detectors in airborne radioactivity monitoring equipment NH-UAV based on a ratio processing method , 2015 .

[11]  R. Menegazzo,et al.  Total natural radioactivity, Veneto (Italy) , 2015 .

[12]  Mirko Reguzzoni,et al.  goGPS: open-source MATLAB software , 2015, GPS Solutions.

[13]  W. Kernan,et al.  Real-time airborne gamma-ray background estimation using NASVD with MLE and radiation transport for calibration , 2015 .

[14]  D. Pfund,et al.  Spectral anomaly methods for aerial detection using KUT nuisance rejection , 2015 .

[15]  R. Brodie,et al.  The 3D inversion of airborne gamma-ray spectrometric data , 2015 .

[16]  G. W. Small,et al.  Real-Time Radionuclide Identification and Mapping Capabilities of the U.S. Environmental Protection Agency’s Airborne Spectral Photometric Environmental Collection Technology , 2015 .

[17]  Applying airborne γ-ray and DEM-derived attributes to the local improvement of the existing individual-tree growth model for diameter increment , 2014 .

[18]  Xiaobin Tang,et al.  Minimum detectable activity for NaI(Tl) airborne γ-ray spectrometry based on Monte Carlo simulation , 2014 .

[19]  Peder Kock,et al.  On background radiation gradients--the use of airborne surveys when searching for orphan sources using mobile gamma-ray spectrometry. , 2014, Journal of environmental radioactivity.

[20]  K. Perez.  Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment , 2014 .

[21]  I. Baroň,et al.  Airborne geophysical survey of the catastrophic landslide at Stože, Log pod Mangrtom, as a test of an innovative approach for landslide mapping in steep alpine terrains , 2013 .

[22]  J. McKinley,et al.  Spatial statistics to estimate peat thickness using airborne radiometric data , 2013 .

[23]  R. Menegazzo,et al.  A multivariate spatial interpolation of airborne γ-ray data using the geological constraints , 2013, 1306.4834.

[24]  Peder Kock,et al.  A real-time statistical alarm method for mobile gamma spectrometry-Combining counts of pulses with spectral distribution of pulses , 2012 .

[25]  Jorg M. Hacker,et al.  The Vertical Distribution of Radon in Clear and Cloudy Daytime Terrestrial Boundary Layers , 2011 .

[26]  A. D. Almeida,et al.  Effective dose rate evaluation from natural gamma radiation in the region of Ribeirao Preto, SP-Brazil , 2011 .

[27]  S. Andringa,et al.  Measurement of the energy spectrum of cosmic rays above 10(18) eV using the Pierre Auger Observatory , 2010 .

[28]  The Pierre Auger Collaboration.  Measurement of the energy spectrum of cosmic rays above 10^18 eV using the Pierre Auger Observatory , 2010, 1002.1975.

[29]  W. K. Hensley,et al.  Accurate modeling of the terrestrial gamma-ray background for homeland security applications , 2009, 2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC).

[30]  C. Dyer,et al.  Comparison of codes assessing galactic cosmic radiation exposure of aircraft crew. , 2009, Radiation protection dosimetry.

[31]  D. Sanderson,et al.  The effect of flight line spacing on radioactivity inventory and spatial feature characteristics of airborne gamma‐ray spectrometry data , 2008 .

[32]  Jan Palczewski,et al.  Monte Carlo Simulation , 2008, Encyclopedia of GIS.

[33]  C. Falguères,et al.  Field gamma dose-rate measurement with a NaI(Tl) detector: re-evaluation of the "threshold" technique , 2007 .

[34]  E. M. Schetselaar,et al.  Guidelines for radioelement mapping using gamma ray spectrometry data : also as open access e-book , 2003 .

[35]  T. Dachev,et al.  On-board aircrew dosimetry using a semiconductor spectrometer. , 2002, Radiation protection dosimetry.

[36]  J. M. Bewers,et al.  Radioactive contamination in the Arctic--sources, dose assessment and potential risks. , 2002, Journal of environmental radioactivity.

[37]  B. Walters,et al.  Calibration of a 7.6 cm x 7.6 cm (3 inch x 3 inch) sodium iodide gamma ray spectrometer for air kerma rate. , 2001, Radiation protection dosimetry.

[38]  Nations United.  sources and effects of ionizing radiation , 2000 .

[39]  R. L. Grasty,et al.  A GUIDE TO THE TECHNICAL SPECIFICATIONS FOR AIRBORNE GAMMA−RAY SURVEYS , 1995 .

[40]  Huang,et al.  Evidence for correlated changes in the spectrum and composition of cosmic rays at extremely high energies. , 1993, Physical review letters.

[41]  Qu Liang,et al.  The United Nations Scientific Committee on the Effects of Atomic Radiation , 1965, Nature.