LED mini-lidar as minimum setup

The LED mini-lidar has been designed and demonstrated as the near range atmosphere monitoring, dust and gas detections. The LED lamp is used as a lidar light source. It is not a special one, and just used as a small status indicator or a spot luminaire. For the atmospheric monitoring in the near range of a few hundreds meters, the energy of 1nJ (=100mW/10ns) is enough for lidar observation in the nighttime. The LED lamp is excited at the high repetition frequency of < 1MHz. The signal-to-noise ratio can be increased by this high frequency even if the receiving photons are a little at each pulse. It is adequate because the spatiotemporal scale of the low-altitude atmosphere is small of a ten seconds and a few tens meters. To pursue such quick motion of the atmosphere and dust, the high-speed photon counter has been developed. It can act with BIN width of 4ns (Spatial resolution 0.6m) at the repetition frequency of <500kHz. The LED mini-lidar has been demonstrated to monitor the actual atmosphere of the observation range of <500m in the nighttime and <100m in the daytime with the receiving lens of 200mmφ. The interest approach is tired to distinguish the dust characteristics by using the counting rate of dust echoes. It is effective in the case that the dust material is given. And for trial, the LED mini-Raman-lidar is developed to monitor certain gas detection in near distance, too.