6. Conclusion

Under the conditions described in section 2, the probability of intercept for a single burst (hop) is proportional to the product of the channel number K and the mean number n of attempts of a receiver in the hop interval T_h (8, 28). The measures multichannel receiver" and "fast scan" have the same effect on probability of intercept and are therefore interchangeable. Both measures for increasing probability of intercept require more effort at the receiver end.

A search receiver optimized for intercepting sufficiently strong signals works with the largest possible number K of parallel channels and a minimum dwell time T_d , ie the shortest possible times for detection, synthesizer settling and signal processing. Short intercept times call for broadband filters. When the de-tection time T_i is shortened, probability of intercept is limited by reduced selectivity to narrowband adjacent-channel signals and broadband interfering signals. If the interfering signal is broadband noise, the required field strength increases proportionally to EDDF (1/ T_i ) for faster detection time T_i . If the FH signal can be observed over a specific operating time, the attempts at detection can be repeated and thus the number of hits increased.