Turn-key Raman lidar for profiling atmospheric water vapor, clouds, and aerosols

Abstract

We describe an operational, self-contained, fully autonomous Raman lidar system that has been developed for unattended, around-the-clock atmospheric profiling of water vapor, aerosols, and clouds. During a 1996 three-week intensive observational period, the system operated during all periods of good weather (339 out of 504 h), including one continuous five-day period. The system is based on a dual-field-of-view design that provides excellent daytime capability without sacrificing nighttime performance. It is fully computer automated and runs unattended following a simple, brief (~5-min) start-up period. We discuss the theory and design of the system and present detailed analyses of the derivation of water-vapor profiles from the lidar measurements.

Can Water Vapour Raman Lidar Resolve Profiles of Turbulent Variables in the Convective Boundary Layer?

“…CARL is a fully autonomous Raman lidar system that is capable of measuring profiles of water vapour mixing ratio, aerosols, and clouds throughout the diurnal cycle for the ARM program (Goldsmith et al 1998). It is located at the ARM CRF site close to Lamont,Oklahoma (36.6 • N, 97.5 • W).…”

“…Since the water vapour mixing-ratio determination is due to the ratio of two Raman signals, both of which have strong blocking of the backscatter at the laser wavelength (Goldsmith et al 1998), the dynamic range of the signals is less than the elastic backscatter signals used in ASR so that the danger of detector overload is reduced. Therefore, it may be reasonable to use the humidity gradient at the top of the CBL for determining z i .…”

“…The data used in the present study were obtained at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Climate Research Facility (ACRF) site near Lamont, Oklahoma, U.S.A. with its Climate Research Facility (CRF) water vapour Raman lidar CARL (see Goldsmith et al 1998 for a detailed description of the lidar). This study is timely, as near-range measurements of CARL were recently improved by the incorporation of advanced detection electronics that combine analogue-to-digital and photon counting into a single package (Newsom et al 2009).…”

Advances in Diode-Laser-Based Water Vapor Differential Absorption Lidar

“…Laser remote sensing -provided by either Raman lidar [3,4] or injection seeded Ti:sapphire-based DIAL systems [5,6,7,8] -are capable of high vertical range resolution and continuous measurements; however, they are traditionally expensive devices to develop and operate. The instrument plus its operational cost is especially relevant since multiple devices -a network of profilers -are required to obtain adequate horizontal spatial resolution.…”

Water Vapor, Cloud and Aerosol Properties on the Tibetan Plateau Using Multi-Lidar Measurements

“…This technique was firstly used by Melfi and Cooney [1] and the profiles of water vapor mixing ratio was retrieved. Due to the development of the high power laser source, the vertical operation range of the Raman Lidars can be extended up to 7 km [4] and throughout the troposphere [5] . Raman Lidars with high power source can also measure atmospheric boundary layer for a complete diurnal cycle with high resolution spatial and temporal resolutions [6] .…”