think I underestimated how hard things could get. If you're just trying to track a frequency-hopping signal where the rest of the power in the band is some mix of Gaussian noise and non-hopping signals, the carrier should be clearly visible as a spike hopping around in the band. As soon as you have two or more frequency-hopping signals however, keeping track of which carrier is which as they hop around looks *much* harder. If they hop at discernibly different times then you can correlate a carrier that disappeared with the one that appeared elsewhere at the same time. This easily described and implemented approach breaks down when two or more signals hop at the same time. Here you might try to associate some sort of signature with each signal to allow you to pair up the new carriers with the old, but you'd have to know more about the situation to say what signatures would be good.
RF finger-printing would do the trick. Any and all RF equipment has its own RF fingerprint no matter how closely they are made at the factory. Now having equipment to RF fingerprint and identify that fingerprint fast enough is another story! Dr0id (andr0id@midwest.net callsign: N9XLM) ( Computer Consulting & Management ) (P.O. Box 421 Cambria, IL 62915-0421) -----BEGIN PGP PUBLIC KEY BLOCK----- Version: 2.6.2 mQENAzCsIi4AAAEH/1hb5+tO/n99Nbppf0ImLJ6AaVZ3NlZP0ZHwRQor00uA129i d4zWixNXxc8t2auaqN+asV99LpIip3/nQzBnjydiumeBdGLF2PR9+6X8X/RrqKa1 dVIukxM5Agg2eM6ih+0J38hgKJ3qzKXSz6sjYmpaxvbXZoHHOLUk/ZtHUKvvEyPw hnJEYnut8NUnIeK56lqeqRw86yoeRKymbfCdjdpgeY2aRwK2FJts8sbb7Fs10s4y jgxWIxIipBznbGUTh1hb2XrLGPENwk3E/qqXQJEsrySbtwdl6VgTVQjhDDEJMitL DYeiQ3W5EgxfcdbM1j2FwYu3P/dM6Y0I8xLMYT0ABRG0NmFuZHIwaWRAb2ljdTgx Mi5jb20gKG9pY3U4MTIuY29tIHN5c3RlbSBhZG1pbmlzdHJhdG9yKYkBFQMFEDCs LO90C7R/GkJcSQEB01cH/0KC3sd+u4OxMku5378SJktoN6QIQYLJ7uVbuV4S51yK NAotCGf4Wl6wwjynzZvXKU0H87oDuMiq7FybgMNL2n+4bQIZi0iz0lIuzwoMDu63 NrHUW9Kz42pOnhrEhrdkHhHL9O5GgD1yc40fJ3qw5h7LQEjDxgypyw0IFILFc34u LeRLliNibxKp8JwAxXNHWSgxu28TQvmnkHi0AHP6tJ/uZYe+4dqJtrMMsYFjzZaz DPmxD+dzbTwlQKtJaP1ZkDI0Sr072wrZDv+G86GyGBMX2lpSafpRitnxuUttjU9o wsQ9Qo5xiH1nZRCs/bDzJe/gng+GHzevixDIITurtNA= =SgPT -----END PGP PUBLIC KEY BLOCK-----