When seismic operations move into very shallow waters, accurately positioning seismic nodes or ocean bottom cables (OBC) on the seafloor can pose a challenge.

The transition zone environment is often highly reverberant, and the vessels used are often noisy and can be a considerable distance from the acoustic transponders used to position the nodes.

What’s more, repeated node positioning operations conducted from vessels are costly and time consuming, especially noting that in shallow water these nodes can be prone to movement, so their positions need to be checked regularly.

Compact and simple to operate – ideal for USVs

To solve these issues, Sonardyne has created our TZ Transceiver. It’s very compact, simple to operate and ideally suited to installation on manned workboats and USVs for conducting acoustic positioning operations with seismic nodes deployed in the transition zone.

In fact, one of our latest orders will see it installed on a Mariner USV provided by Trondheim-based Maritime Robotics’ https://www.maritimerobotics.com/ for a seismic survey to be conducted in the Middle East.

Mariner from Maritime Robotics

The TZ Transceiver works by collecting hundreds of acoustic ranges from transponders such as our TZ/OBC, TZ Transponder and Small Seismic Transponder 6, which are often attached either directly to the seismic node or to the deployment rope nearby. These ranges are merged with the vessel or USV’s GNSS data so that an accurate position of each node can be calculated.

A force multiplier

Mounting our TZ Transceiver onto a USV is ideal because it can follow the mother vessel autonomously and position the nodes as they are being deployed, or, it can be tasked to perform a position verification check to ensure the nodes have not moved.

Maritime Robotics’ Mariner USV, which is currently being fitted with a TZ Transceiver for an end client, acts as a really cost-effective force multiplier by eliminating the need for an additional manned vessel that would otherwise be required to conduct the same routine operations.

The vehicle is designed for both offshore and coastal applications and can be deployed and operated from a larger manned vessel or even over the horizon from a shoreside office, thereby increasing the productivity of the existing survey crew as well as the overall profitability of seismic operations.

Weighing in at 1,900 kg, Mariner is 6 m-long, 2 m-wide and includes a moon-pool and an elevator mechanism for sinking and lowering sensors, such as our TZ Transceiver.

Get in touch

Want to know more about how you can use our TZ Transceiver or our other technologies that are ideal for seismic node positioning and USV operations? Get in touch. We’ll be happy to provide more information.