IGRFT-Based Signal Coherent Integration Method for High-Speed Target with Airborne Bistatic Radar

The airborne bistatic radar has flexible maneuverability and superior adaptability. However, when observing the high-speed maneuvering target, the range migration (RM) and Doppler frequency migration (DFM) resulted from the target's high-speed motion will occur. In addition, the movement of the airborne platform is affected by the air flow, resulting in motion errors, which lead to the shift of echo delay and phase. In this paper, we first analyze and derive the range history model of airborne bistatic radar, then consider the motion errors model of the airborne platform, and deduce the expression of echoes. On this basis, we propose a coherent integration (CI) method based on improved generalized Radon Fourier transform (IGRFT). Specifically, by jointly searching the equivalent motion parameters and error parameters, the proposed method can simultaneously deal with the problem of RM, DFM and motion errors, and achieve CI of target energy. Finally, simulations prove the superiority of IGRFT.