Accuracy enhancement of high-resolution acoustic mosaic images using positioning and navigating data

The author is working on the practical application of the investigation of the underwater offshores structure using ROV equipped with an acoustic camera. The image obtained by mosaic processing of the acoustic camera image is distorted due to the influence of sway during capturing. In this research, we have developed a technology for image correction using position and navigation data from GNSS and INS. The position of the stone embedded in the concrete plate was determined by using the mosaic image created from the image of the acoustic camera with sway suppression by using the rail mechanism and the mosaic image created from the image of the acoustic camera installed in the ROV with sway generated. As a result of verifying the accuracy by the size of the stone, the position error with sway generated was close to the one with sway suppression, and the stone size error was almost close to the actual value.