The Gavia positioning function is provided by either a) INS/DVL  b) USBL

The INS/DVL is a module package also replacable by the twist-lock method of attachment for all modules.  The INS is a ring laser gyro with Kalman filtering and aiding by GPS and/or DVL inputs. 

The INS options are :

i) T24 high spec unit with 3m/hour drift rate quoted

ii) T16 standard spec unit with 20 m/hour drift rate quoted.

For full specifications of these INS units , please refer to Hydro Products.

Doppler Velocity Log Module

Inertial Nav System Module