| Sediment deposited at the foot of landslides stabilizes them temporarily, but removal of such sediment when installing emergency measures requires extra caution to avoid reactivating the landslide. It is therefore necessary to remotely monitor the movement of landslides to avoid secondary disasters for safety reasons as well as for reliable monitoring. One of the main remote monitoring methods is to use a non-prism type optical theodolite, which is useful for measuring the ground displacement from observation stations because no measurement target is needed. However, the measurement error may be higher than that of an optical theodolite that uses targets, and measurement at night is extremely difficult. To overcome these problems, in this study we developed a new method fo remotely setting up targets for an optical theodolite from landslides. |
