Borehole Imaging by Applying 3D Visual SLAM to Borehole Images Acquired in Forward Vision Camera System
Abstract: In the drilling survey, there is a technique called borehole imaging, which examines the
internal ground structure and the presence or absence of faults based on the unfolded panorama created by processing the borehole images taken by a camera. When we investigate the underground to prevent disasters such as landslides, it is desirable to use a portable and simple system including a monocular camera because we set up the system on the mountain slope. The problem with the monocular camera system is that the camera moves off the hole center and rotates around the hole axis. In order to generate the accurate unfolded images, it is necessary to obtain information about the accurate center and orientation of the camera moving inside the hole. For this purpose, we have developed a system to simultaneously estimate the camera pose and the hole center by applying SLAM technology to forward-looking images acquired in a forward vision camera system.
Keywords: borehole imaging, panorama, visual SLAM, forward-looking images, monocular camera, optical flow, disaster prevention engineering, drilling survey.