Abstract: Aiming at the problem of the time difference of arrival (TDOA)/ the scale difference of arrival (SDOA) about the large instantaneous wideband chirp signals, the estimation accuracy is reduced and the algorithm calculation is large under the low signal-to-noise ratio. This paper uses the relationship between time-frequency axis rotation, Wigner distribution and ambiguity function to derive the relationship between the fractional Fourier fourth-order central moment and the SDOA, By finding the position of the central moment of the fractional Fourier fourth-order of the two signals in the angle domain, the SDOA can be estimated..The estimated SDOA is stretched to one signal, and the time domain correlation between the stretched signal and another received signal is calculated, and the TDOA is estimated according to the position of the correlation peak, and qualitatively derive the noise resistance of the algorithm in this paper The simulation results show that compared to TDOA/SDOA estimation algorithm based on the fractional Fourier scaling transform,The algorithm in this paper improves the estimation accuracy of time difference/scale difference under low signal-to-noise ratio, and quantitatively analyzes the anti-noise performance of the algorithm. The algorithm in this paper has better anti-noise performance.