Influence of rain Doppler frequency on MMW Doppler fuze

Guided weapon systems require a proximity fuze device to trigger the explosive warhead. Various proximity fuze types are currently employed. The millimeter wave (MMW) radio Doppler fuze is a potential advantage system, and it is required for a wide range of military application. In this paper, the MMW fuze Doppler Effect is discussed in the encounter course of fuze and target. The target Doppler frequencies (DF) caused by the target moving relative to fuze are calculated at 35 and 95GHz. The relationship of the target DF with the distance between fuze and target is obtained. The rain Doppler frequencies induced by the volumetric rain medium for the interested rain area around target moving relative to fuze are calculated at 35 and 95GHz. The relation of the rain DF with the distance between fuze and the interested rain area are given. The influences of rain DF on target DF are analyzed. It is shown that when the distance between fuze and target is less than about 30m, the difference between the rain DF and the target DF decrease gradually with the distance decreasing. The influences of rain DF clutter on target DF information become gradually bigger with the distance approach, especially, for heavier rainfall, a smaller target and a wider fuze radar beam. Therefore, when the encounter distance between fuze and target is less than about 30m, the influence of the rain Doppler clutter on the target Doppler signal is severe, and need be considered for the MMW Doppler fuze application.