A major limitation of seabed ADCP deployments
Seabed mounted ADCPs have historically been deployed as standalone instruments: The device is pre-programmed with a measurement schedule which allows the ADCP to capture and log water currents at specified time intervals. Once the device has been deployed, it may be months or years until it is recovered, and only then can the data be downloaded and inspected. At best, this results in learning the outcome of the measurements a long time after they were taken. In the worst scenario, the device may have been mis-configured or deployed less than optimally, comprising the data, and/or did not capture any data at all.
What solutions are available?
Some steps have been taken to allow a more instantaneous view of the currents by interfacing a separate acoustic modem with the ADCP. For example, this has allowed users to export industry standard PD0 format data to the surface. However, this process is expensive due to the cost of integration, additional subsea cabling, and a substantially larger payload. What’s more, there is risk associated with achieving acoustic communications in this way, including prevention of data transfer via acoustic telemetry due to limited bandwidth.
Cabled operation is another alternative but suffers from additional risk of damage to the cable, electrical noise pickup from mechanically coupled infrastructure, and is unsuitable in some environments such as deep water or dynamic sites.
What is the Sonardyne solution and what are the benefits?
Origin ADCPs have an integrated acoustic modem, enabling remote communications whilst avoiding the issues of a separate modem or cables.
The Origin 600 ADCP has an MF acoustic modem, and users with an MF topside modem, such as a Modem 6 Nano or MF HPT USBL system, can communicate with a deployed Origin 600 as if it were cabled to a PC or laptop. This goes for Origin 65 too, but this device has an LMF acoustic modem so requires an LMF topside modem for acoustic comms, such as an LMF Dunker 6 or HPT 7000L USBL system.
Just install the Origin Topside software, connect your topside modem to your laptop, and wake up your Origin 600 or Origin 65. You can ask the ADCP how much battery it has left, how much disk space is available, and even check the tilts of the device to make sure it’s level before you leave site.
Forget to configure Origin correctly? Don’t worry. You can set its geolocation acoustically, as well as your assumed salinity and speed of sound in water. Not capturing enough data? No problem – you can reconfigure Origin’s measurement schedule to run faster via acoustic commands, using the same interface as the Origin Scheduler software or the Origin Portal Web UI. Or if a collaborator needs you to run a different schedule, have them send you the file produced by Origin Scheduler and upload it to Origin acoustically. Want to upgrade to run Edge applications? You can upgrade your ADCP to do so, and then upload your preferred Edge app – you guessed it – acoustically.
There are numerous ways by which your ADCP can be checked and configured once in the water. But it doesn’t end there… PD0 records can be acoustically harvested from Origin, so you can see if the quality of the data is good. And if you installed an Edge app that is logging data, those log files can be harvested mid-deployment, allowing you to understand the water and make decisions based on the measurements captured so far. This might even provoke an informed change in measurement schedule to give your mission the best chance of success.
Just for good measure, we’ve made the integrated modem 6G compatible, so it will work with a range of existing and future Sonardyne modem technology. Origin also provides a battery reservoir so that even if there is not enough battery to run ADCP measurements, the integrated modem can still be queried and ranged to aid recovery.
Contact [email protected] for more information.