A New Approach for Spatial Synchronization in Spaceborne/Airborne Hybrid Bi-static SAR
一种新的星机双基地SAR空间同步方法

The spatial synchronization of the antenna footprints is a big methodical and technological challenge in spaceborne/airborne hybrid bi-static SAR(SA-BSAR),due to the fact that there is great difference between the velocities of the platforms.A method by performing beam steering on both sides has been given in the published literature.However,there are some disadvantages in that approach such as short imaging time,requiring complex processing and low azimuth resolution.To overcome these disadvantages,a new approach based on wide-beam illumination is proposed.The feasibility of the new approach is demonstrated by both numerical analysis and simulation results.Several performance parameters for the two methods are quantitatively compared.When the new approach is applied,the scene extension is slightly shorter while the imaging time is much longer and the azimuth resolution is higher.Advantages and disadvantages of each approach and their respective scopes of application are analyzed.