Abstract:The detection of small targets in complex background at high altitude has always been the difficulty of tracking infrared weak targets. A small target detection adopting feature point matching between frames is proposed in this paper. The problem of small target detection in complex background is regarded as the problem of complex background motion estimation compensation of different frames, which can eliminate the effect of background clutter on infrared target and achieve the purpose of background suppression. Then the method is compared with several commonly-used small target detection algorithms like high pass filter and Top-hat filter. The target local signal to noise ratio and false alarm rate are taken as the evaluation index. The experiment results show that after accurate background compensation and frame difference, the target signal-to-noise ratio can increase by more than 2 times and while the detection false alarm rate is lower than 20%.