Comment by wolvoleo
25 days ago
WSPR carries almost no payload data and by default it literally broadcasts your location. You could modify it but it will still take ages to send a short sentence which is probably the last thing you want when you want to avoid getting caught.
Short bursty spread spectrum hopping seems to be more what the military do and they also care deeply about triangulation.
Just to underscore this WSPR sends 50 BITs of data in 110.6 seconds - a data rate of less than 2 baud. It's not practical for really any kind of message passing. Using CW (Morse code) would be at least an order of magnitude faster.
But then you're no longer in the noise floor. That makes you triangulable and bomb-able.
My point is that if you can't do spread spectrum, you've got to think about creative ways to get messages out. Something in the noise floor looks promising even if it's not fast. Further I've seen designs for WSPR that allow the radio to be something like a TTL buffer chip.
If you "announce" yourself you become a target for the signal intelligence folks. Sat phones became a liability in the 2nd gulf war, as they lit up like a beacon saying: "Bomb goes here!".