Technique Of Improved Signal-to-noise Ratio For Imaging Lidar

Imaging lidar has its potential applications in vehicle guidance, helicopter anticollision, visual robot and etc. with its features of highly-directional, high-precision ranging and angular resolution, long range of action, anti-interference and so on. The research is on imaging lidar, which is one of the effective detection tools for assuring cruise missile low-flying and terminal guidance target identification. How to increase the detection probability and weak signal detectability of imaging lidar with 7km range of action is the principal problem. Surrounding the subject, in this thesis the system theory of imaging lidar is researched and the photon counting detection technique is analyzed theoretically. The 1064nm lidar system with direct detection is described. The sub-duplicate relationship of photon accumulative pulse and the signal-to-noise ratio is presented experimentally with the different distant targets, and it has shown that 1.5 times increase in signal-to-noise ratio is given while the photon accumulative pulse is enhanced to 4 times. In addition, the application of photon counting detection technique to the two difference imaging mode is discussed. The results indicate that we can obtain the higher detection probability with broad beam emitting and photon counting detection than the single-beam scanning mode.