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It surprises me that military drones aren't using spread spectrum to make this harder.
by cadr 3y ago
It surprises me that military drones aren't using spread spectrum to make this harder.
- nurettin 3y agoIs that a real thing, or a star trek reference?
- cadr 3y agoA real thing: https://en.wikipedia.org/wiki/Spread_spectrum https://en.wikipedia.org/wiki/Spread_spectrum Fun fact, the famous actress Hedy Lamarr actually was instrumental in inventing it!
- avisser 3y agoYou can tell GP is under 40 or they'd probably remember cordless phones "Now with 900mhz spread-spectrum technology"
- cshimmin 3y agoDefinitely a real thing. Also, during WWII actress Hedy Lamarr developed a system for spread spectrum torpedo guidance to prevent jamming, but the general idea predates that.
- p_j_w 3y agoSpread Spectrum is very real, it was used in 802.11b.
- wkat4242 3y agoYes and Bluetooth. In those cases it's not used to make detection harder though but to be more resilient against interference.
- stoneman24 3y agoYes, it’s a thing. A long time ago, my work involved a frequency hopping, spread spectrum radio link. Can’t say much about it but I’m sure that the technology has improved since then.
- NotSammyHagar 3y agoIsn't good old cdma a spreadspectrum technique, used for cell phones back in the day from quallcomm?
- MegaDeKay 3y agoYes, one of the four basic types. CDMA is the Direct Sequence Spread Spectrum variant. https://en.wikipedia.org/wiki/Spread_spectrum https://en.wikipedia.org/wiki/Spread_spectrum
- nonrandomstring 3y agoHopefully its not pedantic or unwelcome of me to make the distinction between spread-spectrum and frequency hopping. With frequency hopping only one frequency is used at once, and they're selected according to a sequence that matches a shared PRNG. As I understand it, that's what Bluetooth and some Wifi links do. They switch between discrete bands very fast. Spread spectrum is a little different. During modulation, as with FM a series of side bands spread out. Normally we would limit these as they're considered "interference". But with the right modulator you can spread (and indeed encrypt at the RF link level) information into some bands but not others. Although all sidebands are present, to an observer who can't tell which ones carry the data at any moment, it makes no sense to even try demodulating the signal. Neither solutions are much use if you need to communicate back because triangulation alone is enough to find you. Curious if this tallys with your understanding, its over a decade since I had anything to so with this sort of thing. The best summary I recall was in Ross Anderson's "Security Engineering" book (first ed.)
- deleted 3y ago[deleted]
- 3y ago
- thsksbd 3y agoA lot of the drones are off the shelf drones. This war is revolutionary from a tech POV, a lot of the solutions are cobbled together -> see "cope cages"
- wkat4242 3y agoYeah or satellite uplinks that only transmit straight up, much harder to detect and to jam.