Motion Compensation Method for Target Echoes of Shipborne Bistatic HFSWR Using Calibrated Attitude Information

Shipborne bistatic high-frequency surface wave radar (HFSWR) is a new type of HFSWR system, where the transmitting and receiving stations are deployed on different shipborne platforms. It combines the advantages of strong concealment and anti-interference capability of the dual-base system, as well as the mobility and flexibility of the shipborne system. However, for shipborne bistatic HFSWR radar, radar echoes are simultaneously affected by the combined motion modulation of two shipborne platforms, resulting in the broadening of target echoes and induced peaks. So, it is necessary to perform motion compensation processing for the target echo. Inertial navigation attitude information can be used for motion compensation, but the delay of attitude data will affect the compensation performance. In addition, the direct wave signal can be used to estimate the platform attitude information for motion compensation, but the performance of this method will be reduced due to noise. This article proposes a motion compensation method for shipborne bistatic HFSWR target echoes based on calibrated attitude information. First, considering that the motion compensation method of shore-ship bistatic can be adopted, the two-ship modulation model can be transformed into the shore-ship model. Then, the direct wave signal is used as the auxiliary reference source to estimate the attitude information of the shipborne platform, the inertial navigation attitude data are calibrated with it to eliminate the delay error of inertial navigation attitude data, and the calibrated attitude data are used for motion compensation. Finally, the simulation results show that the proposed method can further improve the performance of motion compensation.