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Comment: Re:RF? Heat? (Score 1) 185

by bobbied (#49795467) Attached to: Why Detecting Drones Is a Tough Gig

Again, you folks act like RF energy cannot be controlled, it just goes off in all directions no matter what you do and that there is no way to isolate the jamming energy to small areas. This is not true. Would there be some residual affect outside the intended area? Perhaps, but if you do this right it would not be wide spread, nor would it need to extend more than a few hundred feet beyond the desired areas....

Tell me it's not possible to limit where you put the RF and control the signal strength outside the desired area to acceptable levels... I think you can do that, if you are careful and think about where you put the jammers, what antennas you use and what direction you point them.

Also, GPS jammers are neither expensive nor rare. They are off the shelf and have been for decades and well with the budget of the Secret Service (In fact I'd bet they ALREADY have a few). Directional antennas are also inexpensive and off the shelf, even at the frequencies of GPS. None of this is rocket science... Just a bit of engineering.

Comment: Re:It's not about detection... (Score 1) 185

by bobbied (#49795431) Attached to: Why Detecting Drones Is a Tough Gig

1. Sound is ineffective (ibid.). Video is probably not much better. You didn't mention synthetic aperture radar, which would be my first choice. 2. Do your barriers extend all the way over the top of the object you intend to protect? How about walls and roofs, would they work?

No, they extend as high as you can manage w/o making them obvious. The purpose is to entangle, snare or disrupt the drone in flight by providing obstacles that the distant pilot cannot observe and don't expect. Of course you *could* just build a structure over the whole thing.... But my working assumption is they don't want to change the ascetics of the thing.

3. GPS jamming is illegal. WiFi jamming is illegal if it exceeds a maximum ISM band transmission power.

Yes, it is illegal for you and I, but the government *can* legally do it anytime and any place it wants.

4. Probably a good idea to find the person responsible. 5. Can you? Would you like to share any of them? Even one?

My primary idea is to use nets similar to the way birds are sometimes captured for scientific study. Tie a couple of bean bags to a net, fire it out of a cannon making sure it's rotating. Rotation spreads out the net, snares the drone and the weight of the bean bags disrupts it's flight. There are a couple of variations on this you could try, even a shot gun might be effective but pretty safe to bystanders if the drone is low enough and close enough to the shooter.

Comment: Re:Just wondering (Score 1) 185

by bobbied (#49795379) Attached to: Why Detecting Drones Is a Tough Gig
I disagree. Both the pilot and the aircraft will be emitting in most cases, but even if it's just the pilot, that signal will be a "new" one, which pops up in an area that is of interest, as it will have a line of sight access to the areas being protected. It's not hard to detect that a signal is new, plus it is not hard to locate where a signal source is if you have multiple receivers and just a little bit of technology behind them. A new signal in a predetermined area, especially one with enough strength to be used to pilot a drone into undesired areas should be enough to get you looked at closely in a short time. You won't be lost in a sea of similar RF signals as some here seem to think.

Comment: Re:The things pump out plenty of RF. (Score 1) 185

by bobbied (#49795351) Attached to: Why Detecting Drones Is a Tough Gig
Yea, but a cell phone signal flying over the south lawn is a pretty clear indicator that you have an issue, and if you have data connection with any kind of usable latency, that drone is going to be practically glowing with RF energy, which is 1960's technology detectable.... Everybody seems to think we somehow have a problem coming up with a location of a signal source, when it's EASY to set up multiple receivers and generate a really good idea where that source is in a very short time. And if you limit the coverage of your receivers by using directional antennas, you can easily winnow out all the sources outside the area you are interested in so you don't ever listen to them.

Comment: Re:Just wondering (Score 1) 185

by bobbied (#49795317) Attached to: Why Detecting Drones Is a Tough Gig

But, YOUR signal would be coming late to the party and if I have a system that eliminates commonly monitored signals, locates them using multiple receivers and weeds out the sources that are not in areas where a drone pilot might want to stand/sit/hide. Then if you eliminate all the signals that are simply not strong enough to be useable by a drone flying over the distant lawn I'm trying to protect, there isn't much left to look at but your signal.

Comment: Re:Detecting Drones (Score 1) 185

by bobbied (#49795301) Attached to: Why Detecting Drones Is a Tough Gig

I don't agree... There are ways to carefully control WHERE the jamming is effective and barring multi-path and reflections it is not that hard to be pretty limited outside the bounds. You don't go in with RF blazing in all directions and a 100W PA (although that would do it), you put in multiple directional antennas, putting out a few watts each, watch where you put them and where they are pointed.

I think you could be pretty effective and not bleed over into the public's space, but if you did? So what. Your WiFi router runs under part 15, which means you have ZERO protection from interference legally. For instance, part of the WiFi spectrum overlaps a Ham allocation, this means that I can (as a ham) legally run 1,500W PEP on the WiFi band which would likely wipe out WiFi for the whole town. I might get complaints, but legally I'm golden because part 15 devices have no protection from licensed services.

Comment: Re:Nets (Score 1) 185

by bobbied (#49795251) Attached to: Why Detecting Drones Is a Tough Gig
I never said it was a perfect solution, only that it might be a good idea to try to do this. There really isn't that many WiFi connections out there to monitor, especially ones that would have enough coverage to enable the control of a Hobbyist's drone on a public street. Surely one could winnow down the possible bad guys by keeping track of the environment and filtering out the benign signals and those devices that where connecting to the known Access Points, then looking at the signals left and eliminated any that where too weak to be used. I'm guessing you will have a pretty short list after that...

Comment: Re:Just wondering (Score 1) 185

by bobbied (#49795223) Attached to: Why Detecting Drones Is a Tough Gig
You all act like it's not possible to tell where a specific signal comes from.... All you need is a couple of direction finders tied together and you can develop a pretty good location for *THAT* WiFi signal and decide if it is new, if it's within a specified area and do all this very quickly. So I might not be able to determine exactly what the traffic means, but I can pretty quickly decide if it's a possible threat coming from the clearing over there and not something I've monitored for weeks on end in the office building across the street. How hard is this? If I can image it, I'm sure some smart guys have implemented this already...

Comment: Re:RF? Heat? (Score 1) 185

by bobbied (#49795167) Attached to: Why Detecting Drones Is a Tough Gig

Good luck jamming inertia

Which is why you put up GPS jamming and physical barriers too. Inertial nav is only accurate over short distances, unless you have some external way to calibrate your nav system and can remove the various bias issues caused by vibration, temperature changes and other things that cause changes in the gyros (mechanical, laser ring or otherwise). Usually inertial nav's need to be calibrated, and they do that with GPS (or some other system like LORAN) in order to maintain enough accuracy over time.

Nothing is perfect, but you do the best you can with the resources you have and you live with the risks you cannot afford to fix. I'm suggesting that there is bigger bang for the buck in other things than trying to go out and detect these things in flight.

Comment: Re:Just wondering (Score 1) 185

by bobbied (#49795119) Attached to: Why Detecting Drones Is a Tough Gig

Oh come on..

I'm suggesting we JAM 2.4Ghz around the Whitehouse lawn. Make it impossible for WiFi to work more than a few feet. Then I'm suggesting we track WiFi signals in an effort to catch the pilot, not the aircraft. There are ways to do this w/o being totally disruptive to WiFi service in the surrounding area, or trying to find the needle that pops up in the haystack.

But this is but a small part of the whole plan where physical barriers play a part too....

However, nothing is perfect and nobody has endless resources, so you make a list of risks and how to limit them, pick the things from the list that get you the most risk reduction for the money and live with the rest or go get more money until you CAN live with the risks that are left..

Comment: Re:The things pump out plenty of RF. (Score 2) 185

by bobbied (#49795029) Attached to: Why Detecting Drones Is a Tough Gig

If they are that well funded, catching their drone is unlikely to be your primary worry.

Look, they could just set up a mortar and shell the white house if they where well enough funded, and there is very little you can do to stop a mortar shell in flight and I'm not even going to guess how hard it would be to get your hands on one if you where well funded... Everything has it's limits.

"If a computer can't directly address all the RAM you can use, it's just a toy." -- anonymous comp.sys.amiga posting, non-sequitir