Drift is a consequence of motion between frame dwells. The drift errors can be accommodated by over scanning the frame sample area in an overlap region that ensures that the frame contains the intended image region.
Jitter consists of motions that have predominant effects during the pixel exposure time.
Jitter causes a blurring effect in the image and results in degradation of image resolution. In order to achieve the desired resolution, a technique for precise estimation for the jitter component of the LOS errors is needed. The total LOS motion has two components, namely, the drift and the jitter. The drift causes displacement of the scene whereas the jitter causes distortion of the scene. The concept of the point spread distribution of the LOS error is of interest to us because it allows us to perform the analysis in the frequency domain.