This thesis proposes how to synthesize virtual satellite image depending on geometry. In order to obtain virtual image, modeling and analysis linear pushbroom sensor are considered. Using mathematical model of ground sampling distance (GSD) and ground velocity, the calculation method of the line rate is proposed. GSD is modeled by considering the earth curvature. Line rate is calculated according to change the roll or pitch angle of the satellite. The algorithm to calculate line of sight (LOS) vector is introduced to find the pointed position on the surface of the earth. To improve the accuracy of the LOS vector, digital elevation map (DEM) is considered. Simple interpolation technique is proposed to calculate the pixel value of virtual image. In addition, time-delay integration (TDI) model is applied for more like real image. Finally, some simulation results and the synthesized virtual images are shown to verify accuracy of the modelings.