Accuracy of flight altitude measured with cheap GNSS, radar and barometer sensors: implications on airborne radiometric surveys.
Alberi M., Bottardi C., Baldoncini M., Chiarelli E., Mantovani F., Raptis K.G.C., Realini E., Reguzzoni M., Rossi L., Sampietro D., Strati V.
The distribution of terrestrial radionuclides can be investigated through airborne surveys. An experimental aircraft dedicated to airborne gamma-ray spectrometry has been equipped with seven altimetric sensors: three low-cost GNSS receivers, an inertial measurement unit, a radar altimeter and two pressure and temperature sensors. With the purpose of evaluating their performances, data collected during 11695 seconds of off-shore flights are analyzed in detail. In the (35--2194) m altitude range the median value of the altitude standard deviations is 1.4 m, which implies an uncertainty smaller than 2.5% on the reconstructed radionuclides abundance at ground level.