A model for the signal returns from terrain features for a Synthetic Aperture Radar is developed. A standard range-azimuth geometry is used to divide the surface area into cells for which clutter returns are generated. This geometry is extended to a spherical Earth to introduce effects due to varying terrain height and slope, and to determine areas of shadow. The calculation of phase variation in the returned pulses at the IQ level required to successfully form a SAR is discussed. The technique is illustrated with an example which demonstrates the effect of look angle on SAR images.