The Basic System

A baseline system consists of an electronics stack and a sensor head containing piezoelectric elements and an inertial measurement unit (IMU). An upgraded IMU version of the head is also available, which has similar positioning performance but easier calibration.

The electronics can be packaged in the user’s existing or new enclosure, or an optional Cerulean DVL enclosure can be used.

An optional GPS sensor is available, which can be used to easily initialize an ROV’s position with respect to the standard latitude-longitude world coordinate system. If the optional GPS is not used, the user can provide initialization coordinates from their own GPS or other reference system, or simply use the DVL’s dead reckoning outputs relative to an arbitrary coordinate system starting at (0,0) or another initial coordinate of the user’s choosing.

Additional packaging options include an all-in-one version, with the sensor head and optional GPS integrated into a 300m-rated enclosure, and a most-in-one version, with the sensor head and optional GPS integrated into a 300m-rated enclosure.

The DVL can communicate via standard TTL serial link using ASCII messages, or it can communicate using Ethernet, which also uses ASCII messages. It can emulate a GPS on either interface, sending a standard NMEA-formatted $GPRMC message. Since the $GPRMC message is limited in what information it can send, the DVL can also output a more complete data message at the user’s option.