We explore the determination of motion errors of an aircraft platform from the signum-coded synthetic aperture radar raw signal (SC-SAR data).  The SC-SAR has a one bit representation.  In fact it only provides information about the sign of SAR recorded data. Displacement from the line-of-sight (LOS) direction and nominal forward velocity of SAR platform are estimated from this signal by using the reflectivity displacement method (RDM), which allows the motion error determination directly from SAR raw data