DVL-Aided INS Module

INS Options Include The Kearfott T24, The Kearfott T16 And The IxBlue ROVINS-154

They are integrated with a DVL (and GPS when surfaced) to provide a highly accurate AUV navigation solution. With the T24 INS and 600kHz DVL the navigation accuracy for the AUV going in a straight line is better than 5.5m in 6km (1hr submerged), or ~25m for the T16 (same conditions). ROVINS-154 accuracy figures are available on enquiry. The navigation accuracy is improved when running a lawnmower survey pattern, resulting in about 2m/hour navigation drift rate for the T24/600kHzDVL.

Teledyne Marine

Daytona Beach, US

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Description

The RD Instruments Explorer DVL is a small, low-power consuming DVL designed especially for small platforms operating in the littoral zone. Typically the 600kHz DVL will be used for maximum accuracy (other frequency options are available). The board design of the DVL allows it to be tightly mechanically coupled with the Inertial Navigation System (INS) in a compact package mounted in one Gavia module.

In the DVL, the water current is calculated as the difference between the measured bottom track velocity and the measured water velocity rotated into an Earth-fixed reference frame using the vehicle’s best orientation estimate. The water current is logged on a solid-state flash disk in the Control and Communication Module for post-mission analysis.

Using the altimetry provided by the DVL, the Gavia Depth Pilot can maintain a set altitude above the bottom to perform Sidescan or photographic surveys. While tracking the bottom, the vehicle observes the operating constraints of the minimum and maximum depth specified in the mission plan. The Gavia will not descend beyond the specified maximum depth but rather continue at this depth until the bottom rises above this depth. If the vehicle cannot stay within the specified minimum depth while maintaining constant altitude, the vehicle will proceed to the next leg of its pre-defined survey pattern.

Key Features

Kearfott T24 or T16B INS or IXSEA ROVINS – 154 INS
Teledyne RD Instruments DVL

Specifications

WEIGHT / DISPLACEMENT	Dependent on which option is selected (Kearfott T24, Kearfott T16, or iXBlue ROVINS 154.
FILE FORMAT	Vendor proprietary, exportable to .csv file format
REMOVABLE	Yes, hard coupled and calibrated to DVL/ADCP
DATA STORAGE	Main PC
ACCURACY	Dependent on which option is selected (Kearfott T24, Kearfott T16, or iXBlue ROVINS 154.
SYNCHRONIZATION	The INS data is time stamped by its own internal clock that is synchronized to the GPS PPS output