Abstract: The synchronization by using physical link for coast-ship bistatic SIAR is impractical due to the fact that the receiver is installed on a moving ship. The direct-path wave is used to calibrate the phase and complete the transmit beamforming. The factors that have effects on the accuracy of phase calibration include truncation, discretization, DFT, the motion of the receiver, multi-path and so on. The effects are analyzed and the corresponding compensation is given. The method introduced has been proved feasible by the processing of both the computer simulation and the real data.