The latest tape from bin Laden has reminded me of an idea that I had.
As we know, occasionally al Jazeera or some other news network will receive a videotaped message from a senior member in al Qaeda. The speaker will usually be filmed outdoors holding an automatic rifle and standing in front of an unremarkable rock wall. Other then telling us that the speaker is in a mountainous area, the Allied powers have no way to guess where the message was recorded and to track down the sender.
So I was wondering if we could use principles similar to GPS to secretly pinpoint the location. The idea is this: the message is being recorded using two types of waves – video and audio. We viewers see the video wavelengths and hear the audio frequencies that our bodies are equipped to hear. But what if the US military were to secretly beam light and/or sound waves that vary in intensity according to the distance from the source to the receiver. The video recording equipment would catch these frequencies along with the normal frequencies that we are able to see/hear. And then the folks at the Pentagon would be able to isolate these frequencies, and then depending on how many frequencies we use, we would be able to triangulate the position at which the recording was made.
I am not a physicist or engineer, so don’t know how far-fetched this is. I am guessing the big question is whether standard recording equipment can capture any frequencies beyond the normal ones that people can perceive.
They haven’t done this for several years, since that geologist made a judgement about their location based on the rock formations. The latest videos are shot indoors against a neutral background, like a blanket.
If I understood the OP correctly, I don’t think he was talking about intercepting transmissions from the videotaping itself. Rather, the military would attempt to broadcast hidden frequencies that would be picked up by the recording equipment during filming. Once they get ahold of the recording, whether by mule or otherwise, they’d extract the hidden frequencies from the film and then attempt to triangulate a position.
A stupid analogy would be something like this: You’re standing somewhere in a big field. A dozen of your friends are scattered at predetermined locations around the field and each one is shouting as loud as he or she can. You hear and recognize the voices of three of your friends: John, Jane, and Jack. If you had a map showing you where John, Jane, and Jack are each standing, you’d be able to triangulate your position because you know you’re within shouting range of the three of them and nobody else (this is assuming all your friends shout at the same volume). And if you had trouble hearing, you could record the shouts with a tape recorder, increase the volume, and then listen.
I think his point is that we could identify where the recording was made by decoding the signals captured in the sound portion of the tape. Knowing where the decoding broadcasts originated and finding the frequency, etc, you could figure out where the taping occured.
I think the size of the area, the quality of the tape sound recording, the way that microphones and terrain effect sounds, would make this completely unworkable. Life ain’t like CSI.
Another problem is that basic video cameras, recorders, and tape are not designed to capture subsonic and supersonic frequencies. Add to the problem the fact that these tapes appear to be second or third generation copies.
my take is that the frequencies that the military would have to transmit must be so far out of reach for the human ear/eye (in order to be not detected), that any audio or video equipment would not record it either.
if you could perceive those hidden frequencies - they would just send the tapes through an audio-post processing program and distort it in some manner.
lets face it - those tapes are probably taped on equipment that is probably 5-10 yrs old and at best “household” quality. (I guess the bin laden audio tape was done on a ghettoblaster rather than in a studio)
The video recording gear will only receive and record light that enters the camera lens so the lights that we send would have to be positioned in front of the camera somewhere. If we could do that we already know where the camera is and don’t need the lights.
Same thing with the audio signals. They will only be recorded if the microphone receives them at the recording site and then only over a relatively short range. If we can position our sound trucks that accurately we don’t really need them.
Well that’s not right - cameras pick up REFLECTED light just dandy (they seem to work quite well in daylight without being pointed at the sun). In theory you could have planes flying around with massive strobe lights running at particular frequencies and thus you’d have a good chance of figuring out where any outdoor footage was shot.
Sure, but the background scatters or absorbs light. The background would need to reflect, *i.e.*be the same color as, the particular frequencies. And if it were the same color as those frequencies then all of the reflected light would be that color.
Ah yes. Well, I think we are in agreement that it would only work, even theoretically, if the taping is outdoors or in a place with lots of windows. Most of them now look like they are indooes with a nondescript blanket or wall as background.
I wasn’ t aware that they had moved the videoshooting indoors.
Darn terrorists… always a step ahead of me! :smack:
Still, it seems like there should be some clever way of subtly changing the environment so that the video would give away their location. Where is Sherlock Holmes when you need him?
Maybe we could bombard different areas with EM fields of different frequencies, hopefully causing subtle but detectable—and unique—interferance to whatever videotapes are in the targeted areas.
Of course, with the technology to do THAT, we could probably just scan for his life signs from our orbiting starship.
Or we could just dump a Cobalt isotope over the Afgan-Pakistan border area.
This is actually quite a clever idea, but is somewhat limited by recording fidelity (as has already been mentioned).
Were it not for that, it would be entirely possible to mass-produce little solr apowered infra-red strobe devices, encased in resin plastic to realistically mimic things like stones and seed pods, or any other debris that could reasonably be lying about everywhere. The devices could be programmable by RF, so that you pick a box of them off the shelf and run them through a machine to program a unique strobing pattern, then you take them out and deploy them over an area (by just scattering them) and record the area and the strobe code in a log.
It wouldn’t matter if people found a few of them and destroyed them, because they’d never get them all.
It would then be a case of checking incoming video footage (probably through the same general kind of software that did the SETI@home analysis - looking for signal patterns within a whole bunch of noise) and if a code was detected in the footage, the location could be looked up in the log.
Most CCD and CMOS video cameras are capable of detecting infrared light that is invisible to the naked eye (try using a webcam or camcorder viewscreen to examine the emitter of your TV remote, while you press one of the buttons).
The IR strobe devices would have to ‘paint’ a significant area (which is a problem if you’re powering them from solar energy), the effect would have to be subtle enough not to be obvious to a human watching the footage and the strobe frequency would have to be quite slow in order not to be mangled by video frame rates and ambient noise.
But it could be done. It would be rendered less effective if significant numbers of the emitter devices were discovered and moved about from one area to another and it could be quite easily rendered impotent by simply driving out a long way to a random location to shoot the film, then only releasing it when you’re home safe and never returning to that location.
Now we’re getting somewhere. I am sure that they record in a different location each time, and only send off the tape days or weeks later. But still, I imagine that due to the difficult terrain, they cannot travel too far each time to make the video. So knowing where some of the videos were recorded might give the military a useful pattern to narrow down their search – kind of the same way police map out locations of serial crimes.
What would be entirely possible (and might already be implemented, on the lines of the individual identification already built in color laser printers) is camcorders embedding their serial number as an invisible content of the data stream. That way a video could at least be connected to the store where the camcoder was bought.
I guess you could flood the local markets with cheap video tapes hoping that some would make their way to A-Q, or such. But I guess copies of copies would be another problem; as with just getting to view the cassette but not have it phsyically.