3 ms·
> "low-latency links", says the article. I wonder if they consider 500 ms ping to be low, or if they want to replace Geostationary with Low Earth Orbit. Direct
by adev_ 7mo ago
> "low-latency links", says the article. I wonder if they consider 500 ms ping to be low, or if they want to replace Geostationary with Low Earth Orbit.
Directional laser beams are orders of magnitude to jam compared to radio wave. That alone makes it of big interest for military applications, even with 500 ms latency.
There is several known cases where jamming caused the loss of costly military drones.
https://en.wikipedia.org/wiki/Iran%E2%80%93U.S._RQ-170_incident https://en.wikipedia.org/wiki/Iran%E2%80%93U.S._RQ-170_incid...
Laser comms could prevent that entirely.
- shagie 7mo ago> Directional laser beams are orders of magnitude to jam compared to radio wave. That alone makes it of big interest for military applications, even with 500 ms latency. I am reminded of RFC 1217 - Memo from the Consortium for Slow Commotion Research (CSCR) https://www.rfc-editor.org/rfc/rfc1217 https://www.rfc-editor.org/rfc/rfc1217 2. Jam-Resistant Land Mobile Communications This system uses a highly redundant optical communication technique to achieve ultra-low, ultra-robust transmission. The basic unit is the M1A1 tank. Each tank is labelled with the number 0 or 1 painted four feet high on the tank turret in yellow, day-glo luminescent paint. Several detection methods are under consideration:
- deleted 7mo ago[deleted]
- Spoom 7mo agoI love that this was ostensibly written by Vint Cerf.
- shagie 7mo agoIt's listed in his computer science bibliography https://dblp.org/pid/c/VintonGCerf.html https://dblp.org/pid/c/VintonGCerf.html and https://en.wikipedia.org/wiki/Vint_Cerf#Author https://en.wikipedia.org/wiki/Vint_Cerf#Author Though the edit for that authorship to the RFC came much later. https://datatracker.ietf.org/doc/rfc1217/history/ https://datatracker.ietf.org/doc/rfc1217/history/
- SlightlyLeftPad 7mo agoCould these not be jammed by blasting the same wavelength laser at said geostationary satellite?
- tiagod 7mo agoPlease correct me if I'm wrong, but I guess if you aim well enough, there could be a very long, narrow, non-reflective cylinder in front of the receiver that would block all light that is not coming exactly from the direction of the target satellite.
- Onavo 7mo agoYou will probably need to increase the gain (better lens, photomultipliers) on the receiver photodiode too.
- scottLobster 7mo ago"If you aim well enough" is doing a ton of work there. Precise real-time optical tracking of a satellite from a moving platform is an extremely difficult problem. Even if the satellite itself is geostationary, it would also have to rotate to keep the "cylinder" pointed in the right direction to maintain signal. I suppose you could make a "cylinder" or "cone" broad enough that, if the threat was static, could blot-out attempted jamming from only certain regions while staying open facing toward friendly zones.
- cyberax 7mo agoIt's a geostationary sat. It doesn't move.
- scottLobster 7mo agoNo, but the airplane it would be talking to does. Hard enough when your transceiver is wide open, if you narrow your FOV to a thin cone in order to block jamming signals, the GEO now has to physically track the airplane somehow. Either the whole satellite rotates or the transciever is on a mount that can rotate