RADARSAT-2 is a two-aperture SAR interferometer. When used for GMTI measurements, RADARSAT-2 uses beams in the 40° to 50° incidence angle range to maximise the radial velocity component of the vehicle motion. The airborne experimental SAR reported in this chapter is designed to replicate the RADARSAT-2 GMTI mode resolution and observation geometry and tests the data processing algorithms that can be migrated to the RADARSAT-2 GMTI processor. The greatest difference between the airborne and space-based SAR/GMTI capabilities arises from the relationship between the platform velocity and the along-track velocities of the moving targets. In the airborne case, the target speeds are a significant fraction of the radar speed and can reasonably estimate the azimuthal target speed.