A research group led by Professor Hironobu Suga of Kyushu University has succeeded in making detailed visualization of the USS Emmons, a US warship that sinks to a depth of 40 m off Kouri Island, Okinawa, in an innovative way.
Emmons (total length of about 106m) was inoperable due to the attack of a Japanese special attack aircraft during the Battle of Okinawa at the end of World War II, and was sunk by a consort ship on April 1945, 4, and was discovered in 7.The research group of Professor Suga and his colleagues presented a new method of feeding underwater where satellite positioning systems are not available.Based on the position information obtained from the multi-beam echo sounding for multi-view stereo photogrammetry, a very detailed seafloor topographic map and 2000D model of a 5 cm grid were created.
The multi-beam echosounder (wideband multi-beam echosounder R2Sonic 2022) is a device that measures the seafloor topography in a wide and three-dimensional manner with a fan-shaped beam.We have succeeded in visualizing the seafloor topography at a depth of 1 to 400 m with high accuracy on a grid of 1 to 2 m.So far, deep measurements have been carried out on Kume Island, Ishigaki Island, Kikai Island, Okinawa Island, etc. in the Ryukyu Islands, and high-precision topographical information on shallow waters, which is the pioneer in the world, has been obtained.
This is the first achievement in the world to show a multi-viewpoint stereophotogrammetric map with geographic coordinates for a wide area of 40m x 120m on the seabed at a depth of 30m.Since the target is the war ruins that tell the story of the Battle of Okinawa, it will be a valuable resource for future preservation of underwater war ruins and utilization for peace education.
