TDOT 3 GREENTDOT 3 NIR

Surveying in shallow sea area

Succeeded in surveying long-duration seabed topography using a green laser scanner mounted on a hybrid drone Enables efficient surveying of high-resolution topography

In collaboration with the Port and Airport Research Institute of the National Maritime, Port and Aerospace Research Institute (NMRI), we have demonstrated that the TDOT 3 GREEN drone-mounted green laser scanner on the newly developed GLOW.H hybrid drone can efficiently survey high-definition seabed topography. The demonstration test was conducted on Iriomote Island, Taketomi Town, Okinawa Prefecture, and covered an area of approximately 2.6km in length and 1km in width from land to a depth of approximately 17m. The survey took approximately 4 hours to acquire the continuous topography of the shallow water area and the complex topography of the coral reefs from land.
The survey data (including both water surface and seabed) resulted in a high density with an average spacing of approximately 12cm and a high accuracy with an average error of ±20mm in height. TDOT 3 GREEN has revealed topographic features below wave breaking zones 　that were previously difficult to approach by boat and could not be surveyed, as well as spurs and grooves , which is a characteristic feature of coral reefs. As a result, scientific developments related to coastal landforms are expected to be greatly enhanced, which will also lead to improving the accuracy of predicting wave and landform changes in coastal areas.

*1 Wave breaking zone: an area where waves are affected and deformed by the seabed, causing it to collapse with turbulence. Wave breaking is more likely to occur where water depths become shallower.
*2 Spurs and grooves: grooves and ridge-like features extending perpendicular to the shoreline that are characteristic of coral reefs. They are found at depths down to around 20 m and influence wave deformation.