Abstract: This article shows that, when a complex impulse signal passed through correlation processing, the fluctuation of its ambiguity function will relate to the fluctuation of the input propagated signal of the correlator. We emphasize the case of linear frequency-modulation impulse in the real calculations. The standard deviation of fluctuation of ambiguity function （or its peak value） equals the sum of the square of input signal amplitude fluctuation coefficient and the square of phase fluctuation deviation, i.e.
σ_x^2 =Aσ_Δ^2 _Φ+Bη_A^2
Here, "weight factors" A and B depend on the time correlation radius of the input signals amplitude and phase fluctuations, impulse duration and time delay.