Study of Accuracy Improvement of UAV-Based Seafloor Crustal Deformation Observation

As a countermeasure against the risk of large earthquakes, the GNSS-A observation is being used to observe seafloor crustal deformation. However, it is difficult to improve the frequency and immediacy of the observation due to its high cost and physical limitations of the low-speed platforms. In this study, a GNSS-A observation system using a seaplane-type UAV (HAMADORI 6000) was developed and demonstrated. The reliability of the acoustic ranging was evaluated in the tank test, and we successfully determined the seafloor position with high accuracy the first time in a sea trial. However, it was failed to make an observation the second time due to system trouble. Robustness of the system is an issue for the future.