Accuracy of Flight Altitude Measured with Low-Cost GNSS, Radar and Barometer Sensors: Implications for Airborne Radiometric Surveys. - Matteo Albéri; Marica Baldoncini; Carlo Bottardi; Enrico Chiarelli; Giovanni Fiorentini; Kassandra Giulia Cristina Raptis; Eugenio Realini; Mirko Reguzzoni; Lorenzo Rossi 004; Daniele Sampietro; Virginia Strati; Fabio Mantovani (Sensors, 2017)