Adjustable higher SNR and long-range 3D-imaging cluster lidar based on a coded full-waveform technique

Three-dimensional (3D) lidar imaging technology is developing rapidly in civil, commercial, and military fields. Especially in the military field, lidar with a high signal-to-noise ratio (SNR) and long range is essential. However, high SNR is contradictory to long-range detection, which is a difficult problem to be resolved. In this paper, we propose an adjustable higher SNR and long-range 3D-imaging cluster lidar (C-Lidar) based on a coded full-waveform technique. C-Lidar makes full use of linear mode avalanche photodiode (Lm-APD) multiplexing and space–time domain laser codec technology. The system uses only an 8×8 Lm-APD array to acquire 64×64×64  pixels in a single imaging process within 6.4×10−3  s. Based on the C-Lidar system, we establish a mathematical model to analyze the increased SNR by 18 dB. It is noteworthy that the SNR can be increased much higher when the product of the number of Lm-APDs and the length of the encoding sequence increase. The SNR is adjusted with the product, and C-Lidar changes the SNR by controlling the product. To verify the feasibility of the above theory, we conduct a principle prototype imaging experiment, and the result shows that C-Lidar achieves a clear image at 2 km.