In geosynchronous region, operating a synthetic aperture radar can be advantageous compared to low Earth orbiting radars. Difficulties arise due to the long integration duration requirement of this configuration. Image recovery from the signals recorded during long integration durations depends on the quality of the phase history knowledge. Knowing the phase history accurately requires modelling the phase shifts that might influence the image recovery process. In this project, the orbital perturbation sources that can cause phase shifts have been analysed and modelled. An orbit propagator software was developed in order to observe the effects of the perturbations on the orbit, and a discussion was made about the uncertainties associated with the developed software. It was seen that the models developed in this study are accurate enough to have a GEOSAR mission with 8 hours of integration duration. However, it must be noted that a solar pressure model study was not included in this work, and later it should be carried out in order to cover all of the perturbation sources. Validerat; 20111014 (anonymous)