Indexed by:期刊论文

Date of Publication:2021-01-10

Journal:JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER

Volume:254

ISSN No.:0022-4073

Key Words:Imaging lidar; Monostatic; Scheimpflug lidar; Remote sensing; Laser diodes; CMOS

Abstract:Imaging lidar techniques, featuring of low cost and short blind range, have attracted considerable interests during recent years. However, the bi-static imaging lidar with the transmitter and the receiver placed far away from each other (from a few meters up to 100 m) can mainly operate during nighttime. On the other hand, the monostatic Scheimpflug lidar (SLidar) with the transmitter and the receiver integrated into a single setup suffers from a low quantum efficiency due to the large tilt angle (typically about 45 degrees) of the used image sensor. In this paper, a monostatic imaging lidar with the image sensor placed parallel to the lens plane of the receiving telescope, which is referred to as Shallow Depth-Of-Field Imaging Lidar (SDOFI-Lidar), has been proposed for atmospheric remote sensing. The SDOFI-Lidar system utilizes a 4-W 808-nm multimode laser diode and a 200-mm receiving telescope. The pixel-distance relationship has been established according to geometrical optics. All-day atmospheric measurements can be achieved with much higher signal-to-noise ratios (SNRs) during daytime comparing with the SLidar that employs the same optical configurations. The effect of the defocused backscattering image on the lidar signal has also been evaluated in detail. Inter-comparison measurements have demonstrated that the lidar signals measured by the SDOFI-Lidar generally agreed well with those measured by the SLidar. However, the lidar signal and the corresponding aerosol extinction coefficient could be about 11% and 12% overestimated at around 100 m, respectively, due to the defocusing phenomenon of the backscattering image during horizontal measurements. This work has shown a promising feasibility of employing the SDOFI-Lidar for atmospheric remote sensing if the overestimation of the aerosol extinction in the near range is tolerable. (C) 2020 Elsevier Ltd. All rights reserved.