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Keith W wrote:
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Hint: Look up the accuracy specifications of GPS.

In 7-10 years it will be Galileo. The specifications are a little bit
eklastic as they depend on integration time. If you are talking about
RELATIVE separation this will in fact be only a few centimers, the
accuracy of DGPS.


The accuracy of the GPS systems isnt the issue anyway. Its
handling the problem of separattion of large numbers of drones.

If they have to communicate with each other that introduces
extra weight, a considerable processing issue and a vulnerability
to jamming and/or spoofing.

Frankly you'd probably be better off accepting a certain percentage
of losses due to mid air collisions

Keith



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The issue of transmission is the ability of a controller to take
action.

You dont get it. To maintain separation each drone needs to know
where its neighbours are not just its own position

Also you need some degree of defense in depth. If an enemy
swarm approached you, you would need the ability to direct resources to
that are. One UAV with a LMG is not going to stop a swarm. If however
it had communication technoilogy it might.


The USN isnt going to rely on one LMG for defence

Acceptance of losses due to mid air collisions - OK there will be heavy
losses from a variety of causes. This is, of course, acceptable in a
cheap unmanned system.

To me the amazing thing is the sophistication of COTS. You talk about
weight and cost, but I can put a mobile in my shirt pocket which can do
the most amazing things. Spoofing - all converstaions are routinely
encrypted. Jamming - yes OK but if you are the US you simply put the
jammers out of action.


The US is doing the jamming in this scenarion and dont kid
yourself that encryption cant be broken.


In point of fact use of an error correcting code, such as Reed Soloman,
will go a long way to soving the problem of jamming. You transmit in
bursts, the jammers have be on all the time.


And this is a problem because ?

If you were to have a swarm of UAVs with slightly modified mobile
phones with some aircraft being base stations and commumicating via
satellite you would have gone a fair way to building your system
without too much reaearch.


Psst mobile phones require repeaters in line of sight, there arent
too many in the middle of the Gulf


Keith



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