drone defender

A microwave oven with a knife jammed in the interlock gives you more power and much better deniability.

Cheers

Phil Hobbs

These magnificent creatures will attack the drone:

They're very trainable and could be trained to safely knock the drone down.

Attack video:

Thanks. I missed that. The form has a pull down for "I am interested in..." which offers: US Federal Government use. US State or Local Government use. US Commercial use. Foreign Government use. Foreign Commercial use. I guess that covers everyone except alien visitors from outer space.

Film? Whazzat?

I wish the article had mentioned that the pile of junk was really a pre-prototype artistic impression, using cool looking but worthless components, for the purpose of confusing the potential enemy (who seem to be mostly drone owning American citizens).

It won't work anyway. Any paranoid drone designer will place the GPS antenna on top of the drone, pointing upwards. Any jamming from the ground below just isn't going to be seen by the GPS antenna. There are also quite a few other legal RF bands over which a drone can be controlled. The jammer would need an ELINT system just to find the frequencies in use and determine the modulation characteristics. A wide range frequency hopper or UWB (ultra wide band) system would defeat that. The drone could also be programmed to fly evasive patterns, hover, or return home if the control or GPS signals are lost. Of course, anyone belching copious amounts of RF is a perfect target for an RF seeking HARM missile launched from the drone. Where will it end? Probably yet another anti-anti-missile-missile-missile.

I think drones are okay. Finger wagers always need something to wag a finger at. I guess drones are a fine target for such people in a very literal way. A drone kite might be a good idea, it could save energy by soaring on thermals.

Too complicated and kites are not reliable. Perhaps resurrecting some old technology would be better.

For example, WWI style barrage balloons in the form of "aerial mines". If I make the balloons out of clear cellophane, a camera or ground observer can't optically see them. Just deploy them around the perimeter of your home compound, and wait for the drones to fly into one. A small fragmentation bomb triggered by a proximity detector should be sufficient.

Next up is the "vortex cannon": Drones ride on a cushion of air. Turn the air to turbulence, and they go out of control.

Also available is an EMP gun, designed to induce large voltages in the drone control circuitry. Fly too close and all the semiconductor junctions go poof. You could probably do the same thing with a Tesla coil, to throw lightning bolts, but the neighbors might complain about it ruining radio and TV reception.

I spend an hour last night (after midnight) testing the noise signature of my drone: The unshrouded blades produce quite a bit of ultrasonic noise, which can be used for triggering and targeting. Some kind of ultrasonic noise seeking missile might work. I was thinking of using laser tagging or video guidance for homing, but ultrasonic seeking seems like a better choice. It also has the advantage of not shooting down birds, although there may be a problem with bats.

Sure, but the problem with all such laser and projectile weapons is the collateral damage caused by a miss or an overshoot. Accidentally blinding or shooting down civil or military aircraft is a real risk, especially if your beam diverges. There are also laws against deploying such things.

Boeing's laser does not miss. Your problem would be the falling drone and the damage that brings and causes.

Yep, except that many drone designs are intended to be expendable, which is a nice term for designing them as cheap as possible. One nice way to reduce front end vaporization is to use a fairly narrow band passive RF filter (cavity) on the receiver front end. It still picks up inband RF, but with a narrower bandwidth picks up less power that might fry the front end.

One of the locals flys his custom drones around broadcast radio towers looking for damage, corrosion, broken strands, slipping cable clamps, critters, nests, etc. A few thousand watts nearby didn't bother it in the slightest. However, a different drone pilot flew his machine around Mt Umunhum and Loma Prieta with rather different results. The weather radar near Umunhum caused some loss of control. The multitude of commercial radio transmitters on Loma caused it to become squirrely at about 1 mile away. The difference was that the electronics wasn't shielded. Standard method is to wrap everything in aluminum foil and install ferrite beads in anything that might act as an antenna. Crude, but effective.

Fine. I'll just cover the drone with reflective aluminum foil and chrome plate the blades. Most of the laser beam will be reflected. Certainly, a more powerful laser will do more damage, but there's a limit to how large a sledge hammer will work trying to squash a fly.

That depends on the size of the drone. Mine weighs about 1kg (with camera). I could contrive some situation where that might be a problem, but methinks it unlikely. However, if it is a concern, I could always slow down the descent with the drag from some inflated balloons (parachutes are too messy).

Common "thread" between kites and balloons is the string...

(snip)

The common problem with shotguns, lasers, missiles, vortex guns, EMPs and such is that the drone might fall and cause harm once hit.

Make the kite string sticky, hang netting between your balloons, and a snagged drone is much less likely to fall in a dangerous, uncontrolled manner.

Can you buy a net gun with a lanyard attached to the net so's you can reel your catch in? I can see one taking down a drone but not a 747.

Mark L. Fergerson

On Sat, 05 Dec 2015 09:53:50 -0800, Jeff Liebermann Gave us:

In the case of such a small device, the laser probably heats up the entire target. Crispy critter.

When they do a full sized UAV, they burn a huge hole in the tail piece and it breaks off in most cases.

On Sat, 5 Dec 2015 09:57:33 -0800 (PST), " snipped-for-privacy@bid.nes" Gave us:

What a yuky thing to say. yuk yuk yuk nunyayukness.

Try retro-reflectors. The shooter's equipment may get destroyed itself. :)

joe

Reflectivity of aluminum foil (shiny side) is about 85% at infrared. That's why they make solar ovens from polished aluminum and coat telescope mirrors with vacuum evaporated aluminum. There's not much heat left that will be absorbed unless you use a super sized laser.

So, don't do a full size UAV. Miniaturization has its advantages. Present the smallest possible target to an attacker, etc.

Tail? My quadcopter doesn't have a tail.

On Sat, 5 Dec 2015 19:31:58 +0000, Joe Hey Gave us:

You do not know much about lasers then.

Up close, mirrors reflect the beam. After several hundred or even thousand feet, the mirror is but a small spot in the entire beam FOV and reflects back tenths or hundredths of one percent of the original energy.

Your logic got retrorefelcted.

On Sat, 05 Dec 2015 12:33:36 -0800, Jeff Liebermann Gave us:

Or it would be a hazard to the operator.

If the laser beam spreads out so much that there is too low a power level per unit area to make a dangerous reflection, there is too low an energy level to damage the target.

Why bother to build a laser that spreads out so much that the power at the target is harmless?

How reflective is a mirror? 90%? Just turn up the laser 10dB.`

To take its picture?

Nice, but useless. The problem is that it concentrates the laser on a fairly small spot size. My guess(tm) from the video is about 3 cm diameter. Also from the video, it seems like it took about 10 seconds of continuous exposure in one place to do any damage. This time on target is probably limited by whatever is powering the 2kw laser. The ability for that to work is dependent on the ability of the weapon system to track the target and maintain the spot at a single location. That's easy with a slow and stable fixed wing UAV with limited maneuvering abilities, and rather difficult with a squirrely and erratic quadcopter capable of evasive maneuvers. Optical, IR, and mm wave radar can probably track a UAV, but unless the radar can see the UAV outline, it can't maintain the spot at a given location. Of course, more complexity, more power, and more money will solve these problems, but that's swatting flies with a sledge hammer again.

Also, with a laser, you still have the problem of debris falling out of the sky and crashing in a personal injury attorney's back yard.

No, the eBay one has 15 elements, the battelle one has 12. It also LOOKS to be a different frequency. I'm guessing it might be a GPS jammer. But, with nothing to really compare measurements, I'm kind of guessing.

Jon