The rational polynomial coefficient (RPC) model has recently raised considerable interest in the photogrammetry and remote sensing community. This model is a generalized sensor model that is capable of achieving high approximation accuracy. Unfortunately, in all previous literature, the computation of the parameters of the RPC model depends on initial values for the parameters. In this paper, an algorithm for the computation of the parameters without these initial values is presented. Finally, the algorithm is tested on TerraSAR-X and COSMO-SkyMed SAR imagery. Based on numerous tests, the following conclusion can be drawn. This study found that the RPC model is suitable for high resolution SAR imagery. * Corresponding author.