Abstract:The Discrete Fourier Transform (DFT) has circular shift properties. Similarly, the Discrete Chirp- Fourier Transform (DCFT) motivated by DFT also has circular shift properties. This paper introduces the circular shift of DCFT and proposes a new method to detect chirp. The new method utilities not only the chirp characteristic, but also the noise characteristic, i.e., chirp rates and initial frequencies of chirp are invariant in time, whereas chirp rates and initial frequencies of noise are random in time, therefore, it has better detection performance. Comparing with DCFT, some experimental results are provided to demonstrate the better performance of the detection method proposed by this paper in low Signal-to-Noise ratio (SNR) environments.