关键词: 兵器科学与技术, 分数阶傅里叶变换, 调频引信, 定距方法, 瞬时初始频率, 分数阶相关

Abstract: To improve the ranging accuracy of the frequency modulation（FM）radio fuze under the limit of the little frequency deviation, two ranging methods, i.e. instantaneous initial frequency estimation method and fractional correlation method, for linear FM radio fuze based on fractional Fourier transform (FRFT) are proposed. The ranging principles of the two methods are described, their range resolutions and anti-noise performances are analyzed, and the simulations are carried out to validate these methods. The simulation results demonstrate that the ranging resolutions of the two methods which are affected by the modulation bandwidth rarely are much better than that of the ranging method based on the harmonic wave method. For the known frequency modulation rate, the complexity of the methods is reduced and acceptable for engineering realization. The fractional correlation method is better than the instantaneous initial frequency estimation method in anti-noise performance and can be used in the low signal-to-noise ratio circumstance.

Key words: ordnance science and technology, fractional Fourier transform, frequency modulation radio fuze, ranging method, instantaneous initial frequency, fractional correlation