通过对锯齿调频连续测距系统的差频信号分析可知，由于观测时间的随机性导致同一距离上对应两个不同的差频频率。对差频信号进行时域和频域分析发现，利用两次混频的方法能够解决这种“测距模糊”问题，使信号处理单元的输出信号频率和距离一一对应。利用仿真软件，得到信号处理过程中的时频关系曲线，验证了这种信号处理方法的有效性。

There are two different frequencies corresponding to the same distance caused by the randomness of observation time, based on the analysis on the different frequency of sawtooth frequency modulated continuous wave ranging system. By means of analysis on the difference frequency signal in time domain and frequency domain, it is found that this kind of ranging ambiguity can be settled by mixing frequency twice. The output frequency of the signal processing unit corresponds with the distance one to one at any observational time. The effectiveness of this signal processing method is verified by the signal spectrum and time-frequency curves emulation using the simulation software.