The echo of accelerating targets can be approximated as a linear frequency modulated signal which may degrades the MTD's coherent integration performance.This paper presents an LFM detection method based on both discrete polynomial phase transform (DPT) and the fractional Fourier transform (FRFT).First

the interrelation between frequency resolution

cross-correlation delay

pulse length and integration performance of the classic DPT algorithm are analyzed.The result shows that detection performance of the DPT algorithm with a small time delay can be improved 3dB than classical algorithm.This is helpful to detect accelerating target under low SNR

but causes large parameter estimation error.Second

based on DPT algorithm

the FRFT is applied to further improve the accuracy of chirp rate estimation.When the input signal-to-noise ratio (SNR) is greater than-11 dB

one-dimensional Newton's iteration method can help to improve the operation speed in the fractional domain.Finally

the algorithm complexity and the theory of estimation error are presented

and the validity of proposed algorithm is verified by simulation results which make the theory perfect.