It is important to visualize radioactive substances' position and distribution and estimate their radioactivity levels to reduce the exposure dose of workers in radioactive areas (such as decommissioning worksites of nuclear power stations) and improve nuclear security functions. To visualize the radioactive substance's three-dimensional (3D) location, a directional radiation detector with a cylindrical shield on a simple single-pixel gamma-ray detector was applied to the structure from motion (SfM) technology using an ordinary digital camera. Verification was performed by a system that combines SfM with a CdTe sensor probe having narrow directivity. ²⁴¹Am radiation source's position was visualized by drawing the radiation source's image acquired by the gamma-ray detector on the work area 3D model reconstructed through SfM. Furthermore, as SfM is a simultaneous localization and mapping technology, the system measures the gamma rays while measuring the gamma-ray detector's dynamic position and posture information. The measurements can be acquired while the gamma-ray detector is freely moving in the work area. These methods visualized the radiation source's position and quantitatively estimated the radiation source's radioactivity.

重要的是可视化放射性物质的位置和分布并估算其放射性水平，以减少放射性区域（例如核电站退役现场）工人的暴露剂量并改善核保安功能。为了可视化放射性物质的三维（3D）位置，使用普通的数码相机通过运动（SfM）技术将结构简单的单像素伽马射线探测器上带有圆柱形防护罩的定向辐射探测器应用于该结构。验证是通过将SfM与具有窄方向性的CdTe传感器探头结合在一起的系统进行的。²⁴¹通过在由SfM重建的工作区域3D模型上绘制由伽马射线探测器获取的辐射源图像，可以看到辐射源的位置。此外，由于SfM是同时定位和制图技术，因此该系统在测量伽玛射线探测器动态位置和姿势信息的同时，还可以测量伽玛射线。可以在伽马射线探测器在工作区域中自由移动时获取测量结果。这些方法可视化了放射源的位置，并定量估计了放射源的放射性。