Compared with air-borne SAR, missile-borne SAR has three important characteristics including the high flight speed, the straight movement with non-constant speed and the big squint angle, which bring forward crucial
requirement for the performance of real time, the precision of motion compensation and the azimuth resolution of imaging algorithm. Because of
the fact that the imaging of missile-borne SAR for ground target proceeds after target are found and tracked and the radar antenna always points to target during the imaging process, spotlight SAR mode can be assumed.
SAR cares about imaging geometry, and not the vehicle/platform on which the radar is located... Once you have an image, you can't tell what the vehicle was from which the data was collected... So, no difference...