To improve the efficiency under high false alarms probability conditions

an infrared dim point target trajectory detection algorithm based on short trajectories detection is proposed in this paper.The short trajectories are detected in consecutive frames at first

and then the trajectory association which builds a new trajectory depends on the result of short trajectory is applied to detect the target trajectory.The relationship between false alarms probability and detection probability is deduced

and the detection performance is proved to be better than algorithm based on trajectory association combining with segmentation in single frame.The experimental results indicate that the amount of invalid trajectories can be decreased effectively while the target trajectory is being detected accurately

and the efficiency of target detection is improved.