A DVL fires acoustic pulses from its transducers on board the ROV into the water at various distances from the vehicle to the bottom and detects the reflected pulse from the sea bottom. These received pulses are in turn processed according to the Doppler effect, as well as using proprietary algorithms, in order to accurately estimate the ROV’s speed relative to the sea bottom.
Moving around in subsea areas where USBL positioning is not viable
The Odysseus operates within the confines of towering smokers in the ocean, where USBL positioning is not viable. In such a scenario, it is incredibly valuable to employ a paired DVL and INS solution of the highest grade to permit remote navigation independent of the surface.
Nortek’s DVL1000 “integrated seamlessly”
Pelagic clearly needed a DVL to complement its INS, but its requirements were quite specific: the DVL needed not only to be accurate, but also light – and it had to fit into the compact form of the Odysseus, which was already densely packed with equipment.
Given Pelagic’s requirements, iXblue, the manufacturer of the ROV’s INS, pointed Cassano in the direction of Nortek, citing previous successes in combining instruments made by the two companies.
“They said the Nortek DVL works well and integrates very easily with their INS. So, we talked to Nortek. They were responsive, they were technically expert, and they were incredibly supportive in helping us come up with a solution to our very challenging navigational situation within the constraints of our vehicle,” Cassano says.