Fast Coherent Integration Based on Time-Frequency Reversal Decoupling Transform for Maneuvering Target Detection

Range migration (RM) and Doppler frequency migration (DFM) induced by the maneuvering movement of the target hinder the approach of improving target detection performance through prolonging the integration time. In this article, a fast and robust coherent integration method is presented to efficiently eliminate the migration effects and realize energy integration without requirement of parameter searching procedure. First, the generalized keystone transform (GKT) is performed to correct the quadratic RM. Subsequently, the time-frequency reversal decoupling transform (TFRDT) is explored to remove both linear RM and DFM using one-step complex multiplication. Benefiting from the complete migration elimination through TFRDT operation, target energy can be finely focused by simply applying the 2-D fast Fourier transform without utilizing the complicated scaled Fourier transform. In relation to the existing coherent integration algorithms, the presented GKT-TFRDT features a low-computational cost and is simple to be implemented without ignoring the range curvature and sacrificing much integration performance. Moreover, the effect of blind speed sidelobe and the search for Doppler ambiguity number can be avoided. The computational complexity, multitarget integration, and integration gain of the GKT-TFRDT are analyzed theoretically. Numerical experiments are performed to validate the effectiveness of the GKT-TFRDT method.