Drones

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Tom Ligon
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Re: Drones

Postby Tom Ligon » Wed Jan 28, 2015 3:33 pm

I'd agree with taking it down. But it would be a shame to get arrested for it, depending on your local firearms laws.

Picture this, though (and I realize that at $1500 it is more expensive than a shotgun, and less versatile), one of those t-shirt launching guns, with one of those fishing nets that you cast, the ones with the weights around the edge. Probably bring a quadrotor down quite effectively.

Do you know if these have any punch? Probably quieter than the Remington.

http://www.pyramydair.com/s/m/Gamo_Vipe ... Rifle/1020

GIThruster
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Re: Drones

Postby GIThruster » Wed Jan 28, 2015 3:51 pm

I doubt any sort of air rifle is capable of launching any real weight far and fast enough to catch a drone.

Something like what the "bolomen" carry in Reign of Fire could work:

https://www.youtube.com/watch?v=lhfRDyEyr3k

time index 47 minutes, but then you don't get that very satisfying feeling of seeing the sudden disassembly. If you're gonna skip all the bits flying apart, you can make your own anti-drone weapon pretty easily:

http://thecoolgadgets.com/microwave-gun ... ow-your-a/
"Courage is not just a virtue, but the form of every virtue at the testing point." C. S. Lewis

Tom Ligon
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Re: Drones

Postby Tom Ligon » Wed Jan 28, 2015 5:11 pm

I've had my eye on air rifles that can bring down deer. There are several on the market, but they're not cheap. There are some tests on YouTube that are eye-openers ... thru and thru shots of large antelope. One shot and down.

Lewis and Clark carried a repeating rifle that got the attention of the Indians. It is believed to be a weapon used by the Austrian army. The 18-shot magazine was a fantasy ... the cast iron air bottle charged to 1500 psi was only good for a few shots at high power after about half an hour of pumping, but the Indians didn't know that, or the fact that the expedition had only one such rifle. They could see it managed about a shot a second, which was unheard of in 1803. At full power the weapon was deadly for a few shots.

I've not looked closely at the air shotguns, though. At $200 the one in the link is probably a wimp.

I've known pistol marksmen who could hit stationary targets smaller than a quadrotor at 100 yards. I would not have believed it if I had not seen it. I had to check the target with a 6x scope. This particular marksman could have taken out a hovering quadrotor at that distance one-hand, double action, with a .357 with a 4" barrel. I'm not saying that ability is common.

We used microwave oven magnetrons at EMC2. We tried our best not to launch that power out into free space. It made the ladies in the front office complain about their computers mis-behaving.

GIThruster
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Re: Drones

Postby GIThruster » Wed Jan 28, 2015 6:19 pm

Tom Ligon wrote:We used microwave oven magnetrons at EMC2. We tried our best not to launch that power out into free space. It made the ladies in the front office complain about their computers mis-behaving.
Yes and if they have pacemakers, much worse.

There is a cheap and easy option for anti-droning--a garden hose. Not very interesting but effective.
"Courage is not just a virtue, but the form of every virtue at the testing point." C. S. Lewis

Betruger
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Re: Drones

Postby Betruger » Wed Jan 28, 2015 7:00 pm

Would some kind of harpoon be feasible? With a sticky or penetrating grapple, could the impactor be small enough to keep the "gun" cheap? A net seems inherently more complicated and aerodynamically expensive.
You can do anything you want with laws except make Americans obey them. | What I want to do is to look up S. . . . I call him the Schadenfreudean Man.

GIThruster
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Re: Drones

Postby GIThruster » Wed Jan 28, 2015 7:31 pm

You could use a bow if you like, but you need to take account of where any projectile you use will come down. can't just shoot a bow up into the air and have to crash through the neighbor's window.
"Courage is not just a virtue, but the form of every virtue at the testing point." C. S. Lewis

Tom Ligon
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Re: Drones

Postby Tom Ligon » Wed Jan 28, 2015 8:55 pm

I think we will all be in agreement that this particular ban, at least, is a Good Idea.

http://www.marketwatch.com/story/faa-te ... atest_news

In the meantime, the prohibition on commercial use is preventing some very sensible applications. One of my LinkedIn friends is an archeologist working various sites in Virginia, among them a historic iron works at Falling Creek, near Richmond. This is the first significant effort to make iron in the colonies. He'd like to be able to use a quadrotor for aerial photography, magnetometry, or other valid archeological uses. This is within a controlled area, low altitude, not spying on anyone, hazard to the public approximately zero. An amateur would be perfectly legal flying a quadrotor at the site, as long a they were not trespassing. However, the archeologist can't do it because he is paid, and he can't hire anyone to do it.

Hopefully, the FAA will finish up figuring out what the rules will be soon. They just issued a handful of licenses.

GIThruster
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Re: Drones

Postby GIThruster » Wed Jan 28, 2015 9:13 pm

Well. . .your archeologist friend can no doubt stretch the laws by having a friend pilot the thing. If he plans a magnetic study, I would suggest he use an RC blimp so he can shut down the motors when he takes readings. Those little DC brushless motors create decent fields. People have been mounting cameras on RC helicopters for commercial use for decades. I doubt there is much a problem with a magnetometer on a blimp.
"Courage is not just a virtue, but the form of every virtue at the testing point." C. S. Lewis

Tom Ligon
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Re: Drones

Postby Tom Ligon » Wed Jan 28, 2015 9:31 pm

A magnetometer would probably work pretty well on a quadrotor if on a mast under the craft about a meter or two long. Magnetic fields tend to fall off fast, by about the cube of distance. If you're trying to measure interstellar sub-nanotesla field strength on a probe like the Voyagers, you may put the mags out on a 30-ft boom, but an archeological site will have something like 57,000 nT of Earth's field on it with variations perhaps in the 10 nT range.

Our UAV control systems had built-in magnetometers, with about a 10 nT sensitivity, and usually a 200 nT noise band. Ground testing these we found they could detect underground objects. A couple of dips in the signal during taxi tests bewildered the crew in an early test. The mag was picking up a pair of steel culverts under the runway. You could probably see the motor fields from 2 meters if you used a good fluxgate magnetometer (about 1 nT sensitivity), but it should be readily distinguished from an underground object.

I don't know exactly what is in quadrotor controls, but I expect a MEMS 3-axis magnetometer is part of it, and they're managing to get some directional reference out of it despite the motor fields and other "hard iron" interferences from the vehicle. Batteries containing nickle are problematic ... they re-orient their field each time they're charged, depending on their position. But they need something to set zero rate of rotation on the vertical axis, and a magnetometer is the easiest signal to do this with. GPS does not give direction unless you use two receivers a long distance apart.

The advantage of a quadrotor, at least the better photographic models, is that they can be programmed to run a regular pattern. I mentioned the idea of using an RC blimp to him. He thought that would be fine for photos but would be a problem to make run a grid.

GIThruster
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Re: Drones

Postby GIThruster » Thu Feb 05, 2015 9:32 pm

"Courage is not just a virtue, but the form of every virtue at the testing point." C. S. Lewis

krenshala
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Re: Drones

Postby krenshala » Fri Feb 06, 2015 4:46 pm

One of the videos linked in the comments looked like loads of fun. Drones with cameras on them and the 'pilot' wears a head set to 'see' out the front of the drone, then the four (in the video) pilots race through a wooded section of a park.

GIThruster
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Re: Drones

Postby GIThruster » Fri Feb 06, 2015 5:22 pm

That is a very cool vid!

They are all flying dedicated "Porket Racer 240's" as found here:

http://www.fpv-fly.fr/multirotor/porket ... re=default

The lights and camera on the thing really make it a different experience than it would be otherwise, and racing through a wooded area makes it very interesting. Only a 10A electronic speed control puts this at the very low end of power requirements. Most Park Fliers are 3X that or more.

Looks like great fun!
"Courage is not just a virtue, but the form of every virtue at the testing point." C. S. Lewis

Tom Ligon
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Re: Drones

Postby Tom Ligon » Sat Feb 14, 2015 9:31 pm

Well, maybe they've got it figured out. Time to start looking into a commercial ticket? I'd like to do aerial photography for people like my archeologist friend.

http://www.bloomberg.com/news/articles/ ... s-faa-says

It is interesting to know the FAA has a dollar value it places on a human life ... $9.2 million. They list life-savings for a number of operations, including a small number of deaths doing aerial photography and more doing utilities inspections. Risk to human life due to small quadrotors should be minimal. Definitely, though, whoever has been flying these things in the vicinity of airports needs a proper spanking and their toys taken away. I doubt that will be much of an issue with commercial operators.

hanelyp
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Re: Drones

Postby hanelyp » Sun Feb 15, 2015 4:19 am

The FAA, despite a clear directive from Congress, is dragging it's heels in writing rules for operating of remotely piloted aircraft, outside of a very narrow scope of hobby operation. What commercial operation has been sanctioned is under an exemption process without clear rules. So far the small time commercial RPV operator is out of luck in the US.
The daylight is uncomfortably bright for eyes so long in the dark.

hanelyp
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Re: Drones

Postby hanelyp » Mon Feb 16, 2015 1:51 am

Looks like the FAA is finally taking a step towards licensed commercial use of radio controlled aircraft.
http://www.faa.gov/news/press_releases/news_story.cfm?newsId=18295&cid=TW299
http://www.faa.gov/regulations_policies/rulemaking/media/021515_sUAS_Summary.pdf

Proposed rules are limited to line of sight, daylight only, licensed pilots and registered aircraft. Pilot would be required to pass TSA review, which under the current regime could be highly politicized.
The daylight is uncomfortably bright for eyes so long in the dark.


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