
Robotic submarine snaps images at foundation of Antarctic glacier - rbanffy
https://cos.gatech.edu/news/robotic-submarine-snaps-first-ever-images-foundation-notorious-antarctic-glacier
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Tepix
Very cool stuff. I wonder what they use for the wireless connection.

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beerandt
Usually auv means no cables, and rov means tethered, but they describe their
unit as auv/rov.

So not sure of this specific setup, but for most auvs there are hipap
integrated acoustical modems with limited transmit / receive rates, for
critical status messages and a control link. Everything else is held on hdd
until it surfaces.

[https://www.kongsberg.com/maritime/products/Acoustics-
Positi...](https://www.kongsberg.com/maritime/products/Acoustics-Positioning-
and-Communication/)

In the event of a comm disconnect, it probably has a limited amount of
instructions to continue carrying out (like surveying to the end of the
current grid line) and then holding for a limited amount of time before
aborting to the surface. If a connection can be re-established, it continues.
It's also possible to have navigation connectivity without 2 way comms, so
there are different abort scenarios possible.

If it aborts to surface, then you've got amplified wifi, sat phone, and even
an eprb type beacon.

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errantspark
Abort to surface seems non-trivial in a situation where you're hella deep
under a thicc ice shelf. I wonder what sort of failsafes they've got in place
to handle that particular situation.

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oscully
You are right that abort to surface is non-trivial.

I didn't work on Icefin, but I did write the comms-lost procedure (among many
other things) on a previous ROV/AUV that was deployed in Antarctica to go
under the Ross ice shelf. Britney Schmidt (one of the investigators quoted in
the article) was the PI of the grant for that project as well.

Our AUV was deployed through a hole drilled in the sea ice and controlled via
a fiber optic cable. It was used as an ROV in most circumstances, although we
could preprogram an entire mission to be carried out autonomously. In the
event of the cable breaking the submersible had to navigate via dead reckoning
to get back within range of the acoustic beacon at the deployment spot. The
AUV would follow the acoustic beacon until it was within visual range of a
flashing led rod and then use computer vision to guide the AUV into docking on
that rod so it could be recovered.

If an error occurred under sea ice then we could surface and bring out heavy
equipment to drill a new hole to recover, but the ice shelf was too thick to
drill through. We did have a magnetic beacon on the AUV that helped with
location if we needed to recover after a failure under sea ice.

