【摘要】 目的　研究点目标回波信号的瞬时距离信息提取问题； 方法　在详细讨论点目标回波差频信号频谱结构的基础上，利用单频信号瞬时频率ＩＦ（ｉｎｓｔａｎｔａｎｅｏｕｓ ｆｒｅｑｕｅｎｃｙ）定义、ＦＦＴ方法和计算机仿真，分析差频信号谱结构与信号携带的距离信息的关系； 结果与结论　差频信号的基波频率与目标距离相对应； 所提出的频域最大值跟踪法优于Ｗｉｇｎｅｒ－Ｖｉｌｌｅ 分布（ＷＶＤ）和前向差分法；更多还原

【Abstract】 Aim To study the instantaneous distance information extraction of the point target. Methods Based on discussing the spectral structure of beat frequency signal of the point target echo, the relationship between the spectral structure and the distance information carried by the signal was analyzed by using the definition of instantaneous frequency(IF) of single frequency signal, the methods of FFT and the computer simulation. Results and Conclusion The fundamental frequency of the beat signal is relative to the target distance. The maximum tracking method in the frequency domain was presented for estimating the signal’s IF, which is superior to the WVD and the forward difference method.更多还原