If it is a geo-synchronous satellite, there is no Synthetic Aperture RADAR, SAR, effect. SAR requires relative changes in the location of the transmitting and/or receiving antennae.

If one uses SAR in a continuously cycling mode of Xmit / Receive, etc. We would derive a pseudo Doppler benefit such that, instead of just measuring the return and SINR, we could also measure relative phase differences yielding high resolution 3-D imagery.

I understand that the synthetic aperture technique combines reception signals from elemental areas together. This means that the radiation "view" of the object can be made from a virtual radar aerial the gain of which is synthesisedfrom that of several small real aerials effectively to be much larger than that of each individual. With good signal amplification and control of phasing, the resolution of the image can thereby greatly be improved to a standard which would be otherwise unobtainable due to the prohibitive size and cost of such a real aerial equivalent.

Synthetic Aperture Radar works by taking many looks over a long period of time with an overlap in the beam foot print's on the planet surface. These many looks are integrated together which improves the signal to noise greatly. However, in order to maintain coherency in such long integration periods motion compensation is needs to be performed to increase the time to de-correlation, such that it can achieve the signal to noise required. Synthetic aperture differs from other sharpening techniques like Doppler beam sharpening as it exploits the own vertical own motion and the many looks to synthesises a very long antenna. The increased signal to noise provides longer range and the fast motion of the space vertical provides the ability to get many looks in a shorter time period. But to answer the question it is Long Range ground/surface mapping and 3D topography definition antennas.