Effects of stability of antenna pointing on spaceborne SAR imaging quality

The stability of antenna pointing was researched from the viewpoint of the effects of antenna pointing instability of spaceborne synthetic aperture radar (SAR) on image quality. Based on uniformity weighting antenna, the location and amplitude of the paired-echo resulting from the instability of antenna pointing were derived. The effects of paired-echo on peak sidelobe ratio and integrated sidelobe ratio of impulse response function were analyzed. The Doppler center frequency error due to the instability of antenna pointing was studied. According to the offsets of SAR imaging dependant on the Doppler center frequency error, the required stability of antenna pointing was given. The computer simulation was carried out.