Page 37: of Marine Technology Magazine (November 2019)

LEFT: An inline DVL on the Fusion vehicle have brought creative developments to the ? eld. Teledyne RDI, the successor to the ? rst company to commercialize the ADCP, continues to deliver key technologies, especially DVLs, for un- dersea vehicles. One of the most common unmanned undersea vehicles in service is Hydroid’s REMUS. This vehicle typically employs Teledyne’s compact DVL in the original con? gura- tion of four transducers mounted in a ring. The DVLs in these vehicles augment the GPS positions, recorded at the surface, and often inertial motion measurements to assist the vehicle in tracking its position for improved “dead reckoning.”

The four transducer array is not the only con? guration for a

DVL, nor UUVs the only bene? ciary. Another con? guration is a phased array. This looks like a single transducer face but it is actually an electronically computer-controlled array of transducer elements which creates a series of acoustic “beams” pointing in different directions. Recently, Teledyne introduced the ? rst phased Array DVL rated to 6000 meters, the pioneer 300. For a given size and performance, phased array technology provides greater bottom tracking range than traditional DVLs in this case up to 275 metres from the seabed. The Pioneer DVL was employed on board Vulcan Inc’s deep rated ROV, supported by the R/V Petrel, as it made numerous WWII shipwreck dis- coveries in the Paci? c. This same con? guration is now used in

Teledyne’s latest DVL, the Tasman. Introduced in April 2019.

The ? eld-replaceable phased-array transducer design enhances position accuracy, eliminates the need for speed of sound cor- rection and reduces the drag on an undersea vehicle. This in-

BELOW: The Tasman DVL employs a single, phased array.

Photo: Teledyne Marine www.marinetechnologynews.com

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