They may not tumble, my guess is that they will either continue in the speed/direction or stop hovering in the air for the duration of the jamming signal. (The older, analog-controlled airplane models, where the servo control pulses were sent directly over the transmitter-receiver to the servos, tended to go erratic on jamming, though.) At least if the control link uses some sane not-overly-simple encoding with checksums on the control packets.
For the beginning, play with low average radiated power, ISM-only, and go directional. Less chance somebody will complain.
And start with reading lots of datasheets for the drones, paying attention to the control and telemetry frequencies. If you like the theory, read also something about electronic warfare. US Army Field Manuals tend to be written in a dumb-friendly way so can be read and understood even when youâre tired. Richard A. Poisel wrote a number of ewar books you may find handy; some are even floating around the Net.
Please explain? I briefly read the movie summary but did not make sense in context, and my pop-culture bonus points were traded for the tech ones when I was generating the character.
Unlike fixed-wing planes, which can glide, multicopter failure modes usually result in the copter falling more or less straight down. If the copter is moving quickly when the failure occurs, obviously its existing velocity will be preserved. The copter in question was photographing when it was shot down, therefore it was probably not moving very fast when it was shot, because photographers tend to hover a lot while they frame their shots. Therefore, it probably fell more or less straight down when it fell. Therefore, it was probably not flying over the shooterâs property when it was shot.
Thatâs my logic. You may not agree with it, but itâs consistent with physics.
Depends entirely on the failsafe configuration of the receiver and flight controller. If the copter has altitude-hold, GPS-loiter, or return-to-home functionality, the smart thing to do would be for the pilot to set one of these as the failsafe, which will automatically keep the copter from crashing in the event of a control link dropout.
This doesnât take into account the interaction between the craft and the shotgun pellets (forgive me if that name is incorrect, but really a simple mistake like that does nothing to lessen my point, but with some of the pedants around on this board, this comment is 100% necessary). Nor does it take into account wind.
True that. I mentioned this earlier as a jamming response. Forgot now as the talk was about the yet-cheaper ones which I assumed do not have this capability. But youâre right and this is something worth repeating.
A fun thing is when the homing mode is mis-set. Power on the copter, power on the transmitter, realize you did not read the manual and donât know what to do, power off the transmitter, the copter decides to go home, but the coords set as home are old and possibly entirely elsewhere, and the thing tries to take off and leave. Then, not knowing any better, you have to wrestle with the drone, holding it with one hand and trying to extract and disconnect the battery with the other one. Getting a first propeller-blade cut apparently counts as a rite of passage into drone pilothood.
Pellets is indeed a proper word. (I cheated and looked up wikipedia to be sure. Pays having references on âquick dialâ. Making it a habit proved useful over the years. Set keyword for search for wikipedia, google, google imagesâŚ, and soon you get âctrl-t âw â enterâ in muscle memory.) Shot is the collective word for the pellets in one shell.
The energy transferred by the pellets impact is not likely to be overwhelmingly high. (Some will be spent in transferring kinetic energy from pellet to craft but given the mass difference the transfer will be poor. Some energy will also be spent on shattering the material.) The wind will have more impact but at sane wind speeds and low altitudes it also wonât be likely to have much effect. Low single meters, Iâd guess. Depends also on the damage extent, if the craft goes into free fall immediately or just partially loses power and goes down powered, in semiorderly way.
Qualitatively, youâre certainly right and the effect will be clearly observable. My guess is that it wonât be too significant but I can be wrong and it could be calculated if Iâd be in the mood (anybody else is?).
Edit: Cannot sleep. Brief calculation approach would be approximating the drone as a 1kg 10cm sphere (for aerodynamics and cross-section (for hit probability) purposes, approximate a 12-gauge shotgun with known muzzle velocity (1260 fps or 384 m/s is the ballpark), a shell with No.4 birdshot (weâre shooting a goose), so with 3.3mm pellets, assume lead, so 135 per oz so 210 mg per pellet, E=1/2mv^2 so muzzle energy is 15.5 joule per pellet. Not too flimsy. Assume no aerodynamic losses, so the impact energy is the same, assume 100% energy transfer on impact, assume elastic collision. So 2E=mv^2, so v^2=2E/m, so v=sqrt(2E/m)=sqrt(31 J/1 kg)=5.6. So one No.4 pellet hit to 1-kg object will impair 5.6 m/s delta-v. Not as little as I expected. (Quite less in practice due to lots of other factors we neglected, but it will be roughly in this ballpark.) Calculating the shot pattern, the number of pellets hitting based on distance of the target and the spread of the gun, can be done Sometime Later.
I am corrected, a shotgun shot can move the craft quite a lot. I should have expected that, as my shoulder can attest to quite high recoil of a shotgun. (If you have chance to shoot something, whether a handgun/shotgun/rifle, do it, it is fun; books can tell you only the numbers but only actually feeling the recoil will turn the numbers into something that makes sense. Todo: try an AK47.)
AHHHH! I bet the movie makers completely screwed up the appearance of the EMP. (Whatâs more fun than a NN-EMP (non-nuclear EMP) generator? A nuclear EMP generator!)[1]
[1] âThe worst effects of a Soviet high-altitude test occurred on 22 October 1962, in the Soviet Project K nuclear tests (ABM System A proof tests) when a 300 kt missile-warhead detonated near Dzhezkazgan at 290-km altitude. The EMP fused 570 km of overhead telephone line with a measured current of 2,500 A, started a fire that burned down the Karaganda power plant, and shut down 1,000-km of shallow-buried power cables between Aqmola and Almaty.â
Youâre pretending that the issue at hand had anything to do with a peeping tom or a drone flying over the shooterâs property. Neither was the case. You can play sovereign commando all you like in your daydreams and boasts, but if you shoot a drone that is neither on/over your property or violating your sacred privacy as the shooter in this story did, youâre in the wrong legally (and ethically in my opinion). Do you shoot at windmills because they might be giants also?
How loud are drones? I would be pretty mad (though I would probably not resort to shooting things) if someone were operating a loud thing over and over and over near my house.
In my opinion, very. So loud, if thereâs one within about 50 feet it hijacks oneâs attention. It sounds like something that might like to hurt you and easily could.
um, i played fallout 3 and have an idea where technology is. drones could easily be weapons. i think theyâll eventually have a way to identify themselves, and figure what theyâre doing⌠or be open season. bright red/orange to spot legal ones wouldnât be a bad idea.
oh, and drones can be silent.
I donât believe that gravity propelled shotgun BBs, up to the size of 00 buckshot, could penetrate a normal roofing shingle (or cause significant bodily injury to anything other than a skyward directed eyeball). I canât explain what you found, but I strongly suspect it isnât what you think.
That being said, you need a damn good reason to fire any gun into the air in a residential neighboorhood and based on the available facts, this guy did not have one.
I seem to remember that they make 9mm air-shotguns in Europe, same issue as a real shotgun little pellets have negligible terminal velocity. This should permit anti-aircraft artilleryâing the drone while not carrying the legal and social stigma of a normal internal combustion firearm or the noise(unless you want to pay the $200US firearm silencer registration tax and build a huge device onto the shotgun) though I give 50% odds that discharging an air gun is also illegal inside city limits just on a much lower violation or misdemeanor level.
The real problem is not how to shoot down a drone, it is that the drone was not inside his property when shot down. Though again the guy knew the drone was shotgunned and from where, to report the shooter to the police, by hearing the report of the shotgun.
(edit) Why not an armed fighter drone of your own with some compressed nitrogen and shot canisters to hunt and kill the photo drone while it is still safely over the neighbors property, if you have some left over shot you can strafe the neighbor too as a punishment for droning on before taking a circuitous path home to avoid people knowing you were the perp.
Thatâs possible, Iâm no ballistics expert. But assuming a shotgun wasnât pointed straight up (a fair bet in this case since the drone was over a neighborâs yard) then it seems to me that the shot could still do some damage along a ballistic trajectory.
Terminal velocity is reached in very fast for birdshot, the parabola is maybe 200m on the shooter side and by the time it reaches the downward travel side it is shaped more like a waterfall, nearly all forward energy from the gun is expended into aerodynamic drag and all that is left is to burn off the potential energy of being up in the air.
Unlikely. Unless these were some pretty large gauge pellets (i.e. not birdshot), theyâd be unlikely to cause damage coming down, or even after a certain distance horizontally. Birdshot tends to lose energy pretty quickly. So much so that if you get hit by birdshot from any significant distance while out hunting (not at âDick Cheney hunting distanceâ) it hurts like a mofo, but wonât penetrate skin.
Source: Personal experience⌠(lived in the country for a bit, and pheasant season was interesting to say the least).
As for the pellets in your roof, ?!? No idea. Unless someone shot at relatively close distance, or down at your roof (say from an olde timey dirigible for example), I have no idea how they would penetrate wood. Any chance they were pellet gun pellets? Those things can go frighteningly fast (pending pellet gun, some in excess of 1450 FPS).
