Abstract:  Because of the vertical acceleration of the missile in the diving phase，the magnitude and direction of the velocity are constantly changing，and the flight trajectory is moving along the curve，resulting in a very complex instantaneous slope distance，which causes serious distance migration phenomenon.And there is a serious two-dimensional coupling problem between the azimuth and range direction.A spaceborne-missile bistatic SAR diving forward-looking imaging algorithm was proposed for this problem.The algorithm was based on the characteristics of the bistatic SAR system，built a bistatic trajectory model，performed Doppler frequency correction in the range-frequency domain and azimuth-time domain，and then used the idea of series reversion to derive the two-dimensional spectral expression of the echo signal，followed by distance migration correction，distance and azimuthal compression in the two-dimensional frequency domain to determine the target imaging position and complete the imaging focus.Finally，the feasibility and effectiveness of the algorithm were verified by computational analysis and simulation.The algorithm can realize the detection and differentiation of multiple targets as well as the integration function of detection and fight，which are of value to the military operations.

Key words:  , spaceborne-missile bistatic SAR；diving forward-looking imaging；range cell migration correction；series reversion；Doppler frequency correction