Path: utzoo!attcan!uunet!ginosko!ctrsol!cica!iuvax!mailrus!ames!amdahl!amdcad!military From: smb@ulysses.homer.nj.att.com (Steven M. Bellovin) Newsgroups: sci.military Subject: Re: DFing, was The death of mobile war Message-ID: <26826@amdcad.AMD.COM> Date: 18 Aug 89 04:24:45 GMT References: <26710@amdcad.AMD.COM> <26781@amdcad.AMD.COM> Organization: AT&T Bell Laboratories, Murray Hill Lines: 18 Approved: military@amdcad.amd.com From: smb@ulysses.homer.nj.att.com (Steven M. Bellovin) In article <26781@amdcad.AMD.COM>, baum@apple.com (Allen Baum) writes: > Why is it easy to find the FOO? With the advent of satellite transponders, > and something to compress and squirt a transmission, I would think it would be > very hard to locate a transmitter. I thought it wasn't very easy to begin > with- a lot of hunting and turning antennas, etc. I suspect that a lot depends on how directional the transmission is, and just how good the compression is; however, Kahn reports an incident during World War II, wherein 26 direction-finding stations located a 15-second (compressed) U-boat transmission. (P. 504 in my hard-cover copy.) Use of spread-spectrum techniques might alter that equation a lot, though. --Steve Bellovin