Fig. 1 (IMAGE) Osaka University Caption (a) Appearance of an ultrawide-band millimeter-wave radar mounted on a drone. (b)-(d) Maneuvering the drone inside the chimney and inspecting the inner wall of the chimney while raising the drone. In (d), the chimney opening can be seen above. Credit Osaka University Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.