Long time coherent integration technique is one of the most important methods to improve the radar detection ability of a weak maneuvering target. However, the integration performance may be greatly influenced by the range migration and Doppler migration effects caused by the complex motions of maneuvering targets when long time integration is applied. Besides, the frequency hopping characteristic of the transmitted signal will also result in Doppler migration which cannot be eliminated by the conventional coherent integration method. To deal with this problem, a novel coherent integration method based on phase compensation is proposed. By using the frequency hopping pattern, the Doppler migration is eliminated by adding an extra phase in the twiddle factor of Fourier Transform in this proposed method. Since the phase error is compensated, long time coherent integration can be achieved. The effectiveness of the proposed method is verified by the simulation results and the performance analysis. INDEX TERMS Long time coherent integration, maneuvering target, frequency hopping, Doppler migration.

No abstract