Keywords:Fukushima Daiichi Nuclear Power Station accident, Airborne monitoring, GPS, Positional information, Radiation measurement
Count rates of radiation and the positional information (latitude, longitude, and height) are acquired simultaneously in airborne monitoring. The precision of positional information affects the air dose rates at 1 m height because count rates at 1 m height are calculated by correction of height. In this study, 3 GPS devices are used in addition to 1 GPS device which has been used in previous airborne monitoring. The most appropriate GPS device were determined by comparing precisions of positional information and influences on air dose rates at 1 m height.