against the local aspect. this resulted in scattered data, to which a cosine function was fitted by a least squares curve fit to derive the paramaters' magnitude and direction of the horizontal shift. the method is also used to detect and correct vertical and altitude dependent bias. all four datasets show a systematic horizontal offset(see) which is corrected by the co-registration approach. the co-registration assessment for the ads40/80 and rc30 product showed a negligible offset of