Application research of keystone transform in weak high-speed target detection in low-PRF narrowband Chirp radar

Because of the high speed and the long repeat interval of the radar, there would be serious echo envelope migration while using low-PRF narrowband chirp radar to detect weak high speed targets. The coherent integration method of envelope migration compensation based on keystone transform is studied, the problem of Doppler ambiguity is analyzed, and the influence on the coherent integration effect of Doppler ambiguity degree error and signal band width is simulated, which helps to determine the step of Doppler ambiguity degree search step. The algorithm is introduced and finally experiments on real data are made to testify the algorithm. The results of 128 echo pulses procession show that the SNR could be enhanced by 6 dB, which confirm the effectiveness of this method and improve the ability of weak high speed target detection.