Defense against UAV's

wrote:

:Not necessarily. They could be further apart in good weather and closer
:toghether in bad. As far as wind is concerned COTS provides cheap (1m
r less) GPS.

Hint: Look up the accuracy specifications of GPS.

--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson

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.

wrote in message
ups.com...


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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Keith W wrote:
wrote in message
ups.com...


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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----= East and West-Coast Server Farms - Total Privacy via Encryption =----

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

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.

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.

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.

To do peer-peer communication is something which has been considered, a
lot of development would be needed.

What I think is amazing is the pace of COTS development. It provides a
very good arument against secret projects. What in fact I had in mind
was the provisions of contracts to the perveyors of COTS to advance
their act in military directions. The military could make the new
generation of Internet appear faster. The experts talk about

1) Specificicity. This will involve linguistic research. If you put in
"lock" it will know whether you mean "eclusia" or "cerradura".

2) This is relevant here. The ability of a mobile phone to read a
nearby screen. This is the whole concept of connectivity.

Why not provide funds to get this done? No secrecy required. Tell Al
Qaeda about the strength and breaking strain of the rope.

wrote in message
oups.com...

Keith W wrote:
wrote in message
ups.com...


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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News==----
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Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption
=----

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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Keith W wrote:
wrote in message
oups.com...

Keith W wrote:
wrote in message
ups.com...


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



----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet
News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+
Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption
=----

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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http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

I think you misunderstand the concept. It is one LMG per plane not one
LMG. The whole concept rests on low cost, density and because of
density there will be line of sight communication, although not
necessariyy direct. Communication is of course needed to allow
concentration of forces. You can in fact visualize this as an army of
robots.

Encryption - can it be broken? There have been a number of mathematical
articles on this. If it is breakable you can simply use more bits. A
faster code is noltiplication in a modulus and exlusive OR, but you
need to transmit "die Radstellung" by another method (say RSA).

In article ,
says...

wrote in message
ups.com...


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


That's my position also. One of these days I'll have to set up a
Monte-Carlo simulation to try to judge the collision probability.
As it is, one of my customers still wants to have their autonomous
flying machines exhibit 'flocking and anti-collision' behavior.
Keeping track of where 49 other systems are and where they are
going IS a considerable processing issue---but you can simplify
by ignoring those that are more than 10 seconds flight away
from the system of interest.

Jamming and spoofing can be an issue---but it is somewhat difficult
to jam a spread-spectrum system that only has to communicate
a few hundred meters (from one drone to another).

Mark Borgerson

In article ,
says...
wrote:

:Not necessarily. They could be further apart in good weather and closer
:toghether in bad. As far as wind is concerned COTS provides cheap (1m
r less) GPS.

Hint: Look up the accuracy specifications of GPS.


Hint #2; consider that the improvements due to WAAS are not
available outside North America.

Hit #3: Consider the difference between accuracy and relative
precision. The accuracy needed to transmit a target location
is different from the relative precision you need to keep
from colliding with other UAVs in the swarm.


Mark Borgerson

I think you are ignoring the direction of COTS technology. For many
years there has been a software suite PVM (Parallel Virtual Machine).
This effectively binds together a number of processors together and
runs a single program.

In Java you program in threads. Each thread can be run independently.
The PVM system has the task of deciding which machine should run the
thread. Witth UAVs what you do is this - You have a number of processes
associated with actually flying the airplane, preprocessing of the
sensor suite and firing of the machine gun which are confined to a
specific processor - the local on board processor, and other threads
concerned with the deeper stategy that will run on any processor. PVM
decides which processor to use on the basis of how occupied the
processors are and the rate of data transmission possible. The
programmer does not have to know the details of how resources are
allocated.

You hould really not be thinking about knowledge of aircraft position
to each other, you should be thinking about a Java program and threads.
In Javas I can say

class aircraft{
double xpos,ypos,zpos;//Positions.
double vx,vy,vz;//Velocities;
......
};

I can say in my main module.


int nfriend,nhostile;//Number of aircraft
aircraft *friend, *hostile;

The threads will constantly be updating this. You will have a thread
called "dogfight" which will work out strategy.

The prograamer need not know how the data is transmitted. The software
to do this is around.

http://www.pcworld.ca/news/article/9...b69d0d/pg0.htm

This is an article on the $100 laptop. Note the CONNECTIVITY details.
The $100 features true peer to peer. Is this relevant to UAV defense. I
believe this, and indeed COTS in general to be.

A UAV with a LMG - set a thief to catch a thief! will need this degree
of connectivity. I have looked at connectivity from the standpoint of
the software designer, who does not have to worry about where a thread
is executed. If some links are jammed it will go through other links.

A UAV needs things that a laptop does not, such as an autopilot.
However it does not need an inferface as it is relying on the user
interfaces at base.

Remember - The $100 is NOT science fiction. It is very much a near term
project.