Battery-free wireless imaging of underwater environments
nature.com
nature.com
"Our method consumes five orders of magnitude less power than previously reported underwater wireless imaging systems"
This is accomplished by harvesting energy from acoustics over time and then triggering a circuit to operate for a brief period before recharging.
The method uses "acoustic backscatter" as a means of telemetry for sending the images
The imaging is done with a HM01B0 from Himax Corporation. They capture 3 monochromatic images using red, green, and blue LEDs. Looking at the produced image given by example, I am not sure how accurate the coloring is, but the shape of the object is well defined on a centimeter scale.
Distance between object and camera is under 3.5 meters. The distance they send the image also appears to be about 3.5 - 4 meters. They mention a feasibility to send images over 40 meters with additional tooling.
Device operates around 3.2 volts (triggered by a "super-capacitor" setup) until it depletes to 1.4 volts.
Memory capacity is 12 kbs, and data transfer rate is capped at 1kbps due to the medium. They send one color at a time using 77-bit packets.
I'd love to be proven wrong tho
That sounds pretty abusive towards everything with ears and/or any kind of pressure sensitivity
[0] https://www.geoexpro.com/articles/2010/01/marine-seismic-sou...
I agree that it sounds really obnoxiously loud though. There is a valid reason why marine seismic sources are tightly controlled and some have been banned. This makes old legacy data valuable for those companies that acquired before the bans.
It's orders of magnitude higher than natural ocean sounds.
This is not enough and it doesn't address the louder sounds from submarine communications which are most likely to be the reason for most mammal groundings today.
It is better than it was in the 70's and 80's though. People learned and they adapted, though not always willingly.
Shredded at 1:12. Sad.