Effect of satellite attitude errors on spotlight SAR image

The spotlight SAR usually can realize a high resolution image, which needs the beam having the capability of beam scanning. The satellite attitude swing is a way to realize the beam scanning, but this way will cause the attitude jitter, then the image quality of spotlight SAR will be affected. So the effect of satellite attitude error on spotlight SAR is analyzed in this paper. First the paired echo is analyzed, which is caused by the error of satellite attitude, then the effect of attitude jitter on space-borne SAR image qualities is summarized based on the theoretical analysis and computer simulation. The analytical mathematical expression is deduced, which is useful in analysis of attitude stability and SAR image qualities. Moreover, the swing of the satellite antenna phase center is analyzed, and the effect on peak side-lobe ratio and integrated side-lobe ratio is shown. The computer simulations verify the effect of attitude errors on image quality.