CAT 2.08 - Farming Dots
Search for Amelia Log
After a long transit from American Samoa, the team arrived at the south end of the 2500 square-mile search area. Their first task on site was deploying an array of four Deep Ocean Transponders (DOTs). The DOTs work in concert at depth with the AUV’s navigation system to give the vehicle a precise fix on its location at all times using sonar pings. The DOT configuration consists of two bright yellow flotation spheres attached by a long line to the transponder itself, which is then followed by another stretch of line and a weight to anchor the entire set-up on the seafloor. Later, after the AUVs have finished surveying a particular area and no target has been found, a command is sent to the DOT from the surface that tells it to release the weight. The transponder and flotation spheres float to the surface, where they are recovered alongside the ship by team members using a boathook. The transponders are then re-configured and dropped farther up the line in the search grid, where they await the next AUV sortie.










