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Comment by kevingrahl | Hacker News Reader

Shouldn’t something like this be relatively simple to do with some kind of system with mobile connectivity & GPS housed in some kind of floatable shell?

It wouldn’t have to be powered on for the whole journey (to preserve power) as long as it pings back it’s location from time to time.

And since it’s location is known it should be possible to recover every unit so as not to pollute the oceans with them.

Shouldn’t cost more than $200 per unit, I’d even tend to say that it’s doable for around $100.

This would have the benefit that you can plot the exact course each unit has taken (in real time). And for where there’s no mobile connectivity just save the location locally and push it once connection is regained.

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"Relatively simple" is probably relative.

As others note keeping the electronics alive is going to be hard enough, but the "ping back" is probably the hardest bit.

There is no such thing as mobile connectivity in the middle of the ocean, because there are no cell towers, so your only bet is to use satellite hookups.

Satellite connectivity for things like this is pretty good today, with providers like Iridium providing low bandwidth ping services like their Iridium Short Burst Data Service.

You would use something like the Iridium 9603[0] which idles at 34mA and uses 0.8W to send a message.

That is to say it's all definitely doable, but probably not that simple and much much easier to do today then even 10 years ago.

[0] https://www.iridium.com/products/iridium-9603-3/

Concerning the Iridium emitter, of course you wouldn't let it idle at 34mA. It would need to be shut down with a mosfet like and only be turned on when needed (twice a week for example)

I agree completely, you'd work out what kind of power budget you have (maybe even monitor it if you are using solar) and phone home as regularly as reasonable.

I would think that one hybrid option would be for the balls to enter into a low-power mode when out of cell signal range and simply store their coordinates once ever five minutes. Then when it washes upon the virtual shore, it connects and uploads its track.

What percentage of the coast lines around the world are covered by cell towers, I wonder?

It would be an improvement over having to find them manually, but if you've gone to the effort to engineer an electronics package capable of connecting to a cell tower after years at sea you can probably get it to ping a satellite regularly "for free".

https://en.wikipedia.org/wiki/Global_Drifter_Program

I just read a book on atmospheric remote sensing which had discussion throughout on balloon-based sondes, which are the atmospheric counterpart of ocean drifters.

In the early days of remote sensing, it was thought that these sondes, which are neutrally buoyant and can stay aloft for months, could provide enough data to constrain weather models, especially in the southern hemisphere. And then satellite data with all its calibration problems would not be needed.

It turned out that the sondes tended to drift into certain regions and cluster there, leaving large areas without data. Of course, sondes still play a key role (as do the ocean drifters), but the strategy of just using natural drift to gather data everywhere didn't work.

It’s hard to keep electronics going in the ocean but there is a company called Saildrone that is doing sort of what you are saying. https://www.saildrone.com

As many have said, once you introduce sea water and its accompanying corrosion, along with biofouling, “relatively simple” things become a lot more challenging.

Not to say there haven’t been massively successful drifter studies conducted by oceanographers, though the per unit cost is well more than $200. One of the largest fleets is the Argo[1] float system, with nearly 4000 floats in operation in the world ocean.

[1]: https://en.m.wikipedia.org/wiki/Argo_(oceanography)

Interestingly there are a number of US companies funded under the DARPA Ocean of things program to do just this, and then some. For a company to accomplish such a task the cost is greater but still less than $1k per unit. Everybody wants to put more than just A GPS out there. For one reason, we already understand mesoscale ocean currents well enough that they are not interesting on their own. Also the per buoy cost is high enough that hey, let's just add one more...

It would take a lot of fuel to recover individual probes scattered across the ocean, causing a different kind of pollution.

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