(a) Selected areas in Fukushima Prefecture are modeled in 3D-ADRES using remote sensing data and satellite imagery. (b) Created models are converted into a format suitable for PHITS. (c) The air dose rate distribution is calculated by simulating the gamma rays emitted by radioactive cesium (¹³⁴Cs and ¹³⁷Cs). The colored squares represent modeled air dose rates, whereas the small colored circles represent air dose rates measured in a person-borne survey. Map imagery © DigiGlobe Inc., NTT Data, Google & Zenrin 2018.