Read this tale from The Belmont Club, both as a history lesson and as a warning.Radio frequency energy ("RF") is emitted from all devices that are receiving power.
That RF can be detected and then used to locate you.
Think what advances in technology have been made since the U-boats tracked Allied convoys across the Atlantic.
Think about what Uncle Sugar can do now.
Do you understand now why smart folks think about avoiding tactical radios, while pulling the batteries from their cellphones and any other battery-powered gear?
RF emanations can get you overheard.
Worse yet, they can get you found, fixed, and fried.
Got Reapers?
As a former E-warfare analyst, I've known about this capability for over 40 years, it's not new.
ReplyDeleteRadio transmitters of any kind, when transmitting, are like shining a flashlight in a darkened room.
That also applies to bad people coordinating their own movements in an attempt to come after you via radio, even if they're encrypted. If fact, a signal that is encrypted is a giveaway of who's radiating it because few people have that capability in the private sector. There are exceptions, but not many.
See the easily built Roanoke Doppler DF equipment.
http://www.homingin.com/THRDFSinfo.html
Update: One of the best DF systems around is the Montreal III DF unit, found here: http://ka7oei.com/emm3.html
ReplyDeleteOn a related topic, you'll want a recent copy of the Radio/Tech Modifications books, there's a volume A & B, that tells how to mod handheld radios sold for the amateur bands to operate on other frequencies. http://www.artscipub.com/rtm/RTMa.asp
Yes, these mods do work, at least on the radios I've seen that were modded by others. Remember, transmitting out of band or in areas requiring a license may be illegal.
Final paragraph of the article:
ReplyDelete"But it is the human analysts who make it all work."
Weak link in the chain...
U-1105 as well.
ReplyDeletehttp://en.wikipedia.org/wiki/German_submarine_U-1105
Lieut-Gen Metz has urged the Pentagon to share top-secret methods used by US forces to detect the so-called Improvised Explosive Devices and the terror networks which build them. … The officer said IEDs were often located using unmanned drone aircraft equipped with sensors to detect where ground has been disturbed to bury explosives. It is understood Britain does not possess this technology.
ReplyDeleteAny thoughts on implications for caching?
on IED detection...
ReplyDeletehttp://www.youtube.com/watch?v=gZht4Qvjorg
Reflection or return loss on a transmitter is detectable at a much shorter range than the range of that transmitter. EMF is also detectable but at a much shorter range. In other words they will be close if they detect you. For most of the handheld radio types they will be well within rifle range.
ReplyDeleteNot sying its smart to transmit over open channels but keep in mind they use short range hand helds as well. Whats good for the goose and all.
"Any thoughts on implications for caching?"
ReplyDeletePlowed field?