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The article talks about tethered barges for a transatlantic link… How would that work when the dishes need to be pointed at each other and the barge will be bo

The article talks about tethered barges for a transatlantic link… How would that work when the dishes need to be pointed at each other and the barge will be bobbing back and forth? Does the signal spread enough to cope with that?

cpcallen 10y ago
I wouldn't think it would be too hard to use a gyro-stabilized gimbal to keep the antennae pointing in the right direction. Most drone quadcopters used for aerial filming already do this.
- gravypod 10y ago
  I think the hard part is the salt-water environment. Any bearing wants lubricant and putting anything that complicated in salt water sounds like a bad idea .
- onion2k 10y ago
  Gimbals can only do so much. In the mid-Atlantic ocean wave heights are between 6 feet and 20 feet. That's not going to feel like much if you're on an oil tanker, but a relatively small barge is going to move up and down a lot.
gravypod 10y ago
They don't need to be pointed at each other. The antennas aren't very high gain which means they will still hit around the target. But yes it is difficult. Gain, even though this isn't a correct analogy, is like the difference between a laser and a flash light. The laser is a very narrow beam, which is a high gain antenna, and the flash light is very low gain. What I'd be worried about are waves and storms knocking out the network. I would assume that microwaves would go through a wave since they are so nigh energy but they are used by the navy for wave-detection (radar is basically microwave). Moving around isn't too bad because they only need to be on at about 50-60deg. Heavy waves would knock out the network like you are worried as well since I think microwaves would be able to punch through the ionosphere most of the time (UHF is usually used for sat-coms by the military).
- dom0 10y ago
  Microwaves have a penetration depth in water of just a couple centimeters. The higher the frequency the less. I guess K-band is probably already below one centimeter.
noonespecial 10y ago
It would probably be more like a large vertical tower with most of its mass floating underwater than a flat barge with an antenna mast on the deck. This would mean even large waves would hardly affect it. The bigger problem is you'd need at least 70 of them to cross the atlantic.
- tshannon 10y ago
  > The bigger problem is you'd need at least 70 of them to cross the atlantic. That actually doesn't sound too bad. I would've expected that number to be much higher. I wonder how that cost would compare to the thousands of miles of cabling we currently use.
- cellularmitosis 10y ago
  Hmm, like a SWATH but a bouy! https://en.m.wikipedia.org/wiki/Small-waterplane-area_twin_hull https://en.m.wikipedia.org/wiki/Small-waterplane-area_twin_h...

cpcallen 10y ago

I wouldn't think it would be too hard to use a gyro-stabilized gimbal to keep the antennae pointing in the right direction. Most drone quadcopters used for aerial filming already do this.

gravypod 10y ago
I think the hard part is the salt-water environment. Any bearing wants lubricant and putting anything that complicated in salt water sounds like a bad idea .
onion2k 10y ago
Gimbals can only do so much. In the mid-Atlantic ocean wave heights are between 6 feet and 20 feet. That's not going to feel like much if you're on an oil tanker, but a relatively small barge is going to move up and down a lot.

gravypod 10y ago

They don't need to be pointed at each other. The antennas aren't very high gain which means they will still hit around the target. But yes it is difficult. Gain, even though this isn't a correct analogy, is like the difference between a laser and a flash light. The laser is a very narrow beam, which is a high gain antenna, and the flash light is very low gain. What I'd be worried about are waves and storms knocking out the network. I would assume that microwaves would go through a wave since they are so nigh energy but they are used by the navy for wave-detection (radar is basically microwave). Moving around isn't too bad because they only need to be on at about 50-60deg. Heavy waves would knock out the network like you are worried as well since I think microwaves would be able to punch through the ionosphere most of the time (UHF is usually used for sat-coms by the military).

dom0 10y ago
Microwaves have a penetration depth in water of just a couple centimeters. The higher the frequency the less. I guess K-band is probably already below one centimeter.

noonespecial 10y ago

It would probably be more like a large vertical tower with most of its mass floating underwater than a flat barge with an antenna mast on the deck. This would mean even large waves would hardly affect it. The bigger problem is you'd need at least 70 of them to cross the atlantic.

tshannon 10y ago
> The bigger problem is you'd need at least 70 of them to cross the atlantic. That actually doesn't sound too bad. I would've expected that number to be much higher. I wonder how that cost would compare to the thousands of miles of cabling we currently use.
cellularmitosis 10y ago
Hmm, like a SWATH but a bouy! https://en.m.wikipedia.org/wiki/Small-waterplane-area_twin_hull https://en.m.wikipedia.org/wiki/Small-waterplane-area_twin_h...