On Wed, 2 Nov 2016 20:45:29 -0400, "Percival P. Cassidy"
wrote:

On 11/02/2016 07:57 PM, Jeff Liebermann wrote:

Interesting that even balloons
were sufficient - so one could launch small weather balloons that have a
maximum height (pin pop by altitude) around a drone? Safe at airports...

Those have also been invented and are known to work well. They're
called "barrage balloons".
https://www.google.com/search?q=barrage+balloon&tbm=isch
Unlike the drone propellers getting tangled with the rubber balloons,
the WWII version had the German bombers smashing into the tethering
cable, suspended nets, or sometimes cables strung between balloons.

I remember a barrage balloon site just across the fence from the farm
where I grew up on the North Downs in the UK, but I don't recall hearing
whether that particular installation brought down a German plane. My
mother and I went to stay with family far away from London for part of WWII.

That was before my time. As I understand it, the barrage balloon were
modestly effective against low flying threats, such as V1 flying bombs
and JU87 dive bombers. They did little against high flying threats,
specifically high altitude bombers, and nothing against the V2 rocket.
Some details and numbers:
http://www.airpower.maxwell.af.mil/airchronicles/apj/apj89/sum89/hillson.html

For defense against low flying chainsaws, I would recommend simply
suspending any style of entanglement wires from an aerostat
(stationary balloon). It's quite difficult to see small obstructions
from a FPV (first person view) drone. Running into a dangling cable
would destabilize the drone, even if the turbines (propellers) were
shrouded. If sucked into the chainsaw, the wires would become
entangled in the cutting mechanism. The dangling wires could also be
configured as "aerial mines" which would explode on contact.

However, all this requires an unobstructed air space to deploy the
aerostats. Using this system to defend a stand of timber might be
problematic.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558