Effect of high altitude nuclear electromagnetic pulse upon phone call

Interrupt effects on telephone excited by high altitude electromagnetic pulse(HEMP) was investigated. Under the electromagnetic environment produced by a bounded-wave EMP simulator, probability distributions of phone call interrupt excited by 1976 HEMP and 1996 HEMP were presented and compared, and frequency spectra and electromagnetic norms were applied to analyse this effect’s mechanism. The results show that the interrupt threshold for 1996 HEMP is slightly lower than that for 1976 HEMP because the former contains more high frequency and both probability distributions can be fitted by normal distribution.