scholarly journals Diffuse sunlight based calibration of the water vapor channel in the upc raman lidar

2018 ◽  
Vol 176 ◽  
pp. 05035
Author(s):  
Constantino Muñoz-Porcar ◽  
Adolfo Comeron ◽  
Michaël Sicard ◽  
Ruben Barragan ◽  
David Garcia-Vizcaino ◽  
...  
Keyword(s):  
Water Vapor ◽  
Raman Scattering ◽  
Calibration Factor ◽  
Raman Lidar ◽  
Lidar System ◽  
System Parameters ◽  
Vapor Channel ◽  
Technical University

A method for determining the calibration factor of the water vapor channel of a Raman lidar, based on zenith measurements of diffuse sunlight and on assumptions regarding some system parameters and Raman scattering models, has been applied to the lidar system of Universitat Politècnica de Catalunya (UPC; Technical University of Catalonia, Spain). Results will be analyzed in terms of stability and comparison with typical methods relying on simultaneous radiosonde measurements.

scholarly journals Study and mitigation of calibration factor instabilities in a water vapor Raman lidar

2017 ◽  
Vol 10 (7) ◽  
pp. 2745-2758 ◽  
Author(s):  
Leslie David ◽  
Olivier Bock ◽  
Christian Thom ◽  
Pierre Bosser ◽  
Jacques Pelon
Keyword(s):  
Water Vapor ◽  
Lower Troposphere ◽  
Satellite System ◽  
Calibration Factor ◽  
Raman Lidar ◽  
Lidar System ◽  
Short Term ◽  
Term Stability ◽  
Water Vapor Mixing Ratio

Abstract. We have investigated calibration variations in the Rameau water vapor Raman lidar. This lidar system was developed by the Institut National de l'Information Géographique et Forestière (IGN) together with the Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS). It aims at calibrating Global Navigation Satellite System (GNSS) measurements for tropospheric wet delays and sounding the water vapor variability in the lower troposphere. The Rameau system demonstrated good capacity in retrieving water vapor mixing ratio (WVMR) profiles accurately in several campaigns. However, systematic short-term and long-term variations in the lidar calibration factor pointed to persistent instabilities. A careful testing of each subsystem independently revealed that these instabilities are mainly induced by mode fluctuations in the optic fiber used to couple the telescope to the detection subsystem and by the spatial nonuniformity of the photomultiplier photocathodes. Laboratory tests that replicate and quantify these instability sources are presented. A redesign of the detection subsystem is presented, which, combined with careful alignment procedures, is shown to significantly reduce the instabilities. Outdoor measurements were performed over a period of 5 months to check the stability of the modified lidar system. The calibration changes in the detection subsystem were monitored with lidar profile measurements using a common nitrogen filter in both Raman channels. A short-term stability of 2–3 % and a long-term drift of 2–3 % per month are demonstrated. Compared to the earlier Development of Methodologies for Water Vapour Measurement (DEMEVAP) campaign, this is a 3-fold improvement in the long-term stability of the detection subsystem. The overall water vapor calibration factors were determined and monitored with capacitive humidity sensor measurements and with GPS zenith wet delay (ZWD) data. The changes in the water vapor calibration factors are shown to be fairly consistent with the changes in the nitrogen calibration factors. The nitrogen calibration results can be used to correct the overall calibration factors without the need for additional water vapor measurements to within 1 % per month.

Lamp mapping technique for independent determination of the water vapor mixing ratio calibration factor for a Raman lidar system

2011 ◽  
Vol 50 (23) ◽  
pp. 4622 ◽  
Author(s):  
Demetrius D. Venable ◽  
David N. Whiteman ◽  
Monique N. Calhoun ◽  
Afusat O. Dirisu ◽  
Rasheen M. Connell ◽  
...  
Keyword(s):  
Water Vapor ◽  
Calibration Factor ◽  
Mapping Technique ◽  
Mixing Ratio ◽  
Raman Lidar ◽  
Lidar System ◽  
Independent Determination ◽  
Water Vapor Mixing Ratio

scholarly journals Multi-wavelength Raman lidar, sunphotometric and aircraft measurements in combination with inversion models for the estimation of the aerosol optical and physico-chemical properties over Athens, Greece

2012 ◽  
Vol 5 (1) ◽  
pp. 589-625
Author(s):  
R. E. Mamouri ◽  
A. Papayannis ◽  
V. Amiridis ◽  
D. Müller ◽  
P. Kokkalis ◽  
...  
Keyword(s):  
Water Vapor ◽  
Chemical Properties ◽  
Urban Site ◽  
Aircraft Measurements ◽  
Raman Lidar ◽  
Lidar System ◽  
Aerosol Composition ◽  
Microphysical Properties ◽  
Multi Wavelength

Abstract. A novel procedure has been developed to retrieve, simultaneously, the optical, microphysical and chemical properties of tropospheric aerosols with a multi-wavelength Raman lidar system in the troposphere over an urban site (Athens, Greece: 37.9° N, 23.6° E, 200 m a.s.l.) using data obtained during the European Space Agency (ESA) THERMOPOLIS project which took place between 15–31 July 2009 over the Greater Athens Area (GAA). We selected to apply our procedure for a case study of intense aerosol layers occurred on 20–21 July 2009. The National Technical University of Athens (NTUA) EOLE 6-wavelength Raman lidar system has been used to provide the vertical profiles of the optical properties of aerosols (extinction and backscatter coefficients, lidar ratio) and the water vapor mixing ratio. An inversion algorithm was used to derive the mean aerosol microphysical properties (mean effective radius – reff), single-scattering albedo (ω) and mean complex refractive index (m) at selected heights in the 2–3 km height region. We found that reff was 0.3–0.4 μm, ω at 532 nm ranged from 0.63 to 0.88 and m ranged from 1.45 + 0.015i to 1.56 + 0.05i, in good accordance with in situ aircraft measurements. The final data set of the aerosol microphysical properties along with the water vapor and temperature profiles were incorporated into the ISORROPIA model to infer an in situ aerosol composition consistent with the retrieved m and ω values. The retrieved aerosol chemical composition in the 2–3 km height region gave a variable range of sulfate (0–60%) and organic carbon (OC) content (0–50%), although the OC content increased (up to 50%) and the sulfate content dropped (up to 30%) around 3 km height; in connection with the retrieved low ω value (0.63), indicates the presence of absorbing biomass burning smoke mixed with urban haze. Finally, the retrieved aerosol microphysical properties were compared with column-integrated sunphotometer data.

scholarly journals Development of Raman LIDAR System to Measure Vertical Water Vapor Profiles and Comparision of Raman LIDAR with GNSS and MWR Systems

2011 ◽  
Vol 22 (6) ◽  
pp. 283-290
Author(s):  
Sun-Ho Park ◽  
Duk-Hyeon Kim ◽  
Yong-Gi Kim ◽  
Mun-Sang Yun ◽  
Hai-Du Cheong
Keyword(s):  
Water Vapor ◽  
Raman Lidar ◽  
Lidar System

scholarly journals Characterization of Water Vapor Fluxes by the Raman Lidar System Basil and the Univeristy of Cologne Wind Lidar in the Frame of the HD(CP)2Observational Prototype Experiment – Hope

2016 ◽  
Vol 119 ◽  
pp. 25006
Author(s):  
Paolo Di Girolamo ◽  
Donato Summa ◽  
Dario Stelitano ◽  
Marco Cacciani ◽  
Andrea Scoccione ◽  
...  
Keyword(s):  
Water Vapor ◽  
Raman Lidar ◽  
Lidar System ◽  
Wind Lidar

scholarly journals Multi-wavelength Raman lidar, sun photometric and aircraft measurements in combination with inversion models for the estimation of the aerosol optical and physico-chemical properties over Athens, Greece

2012 ◽  
Vol 5 (7) ◽  
pp. 1793-1808 ◽  
Author(s):  
R. E. Mamouri ◽  
A. Papayannis ◽  
V. Amiridis ◽  
D. Müller ◽  
P. Kokkalis ◽  
...  
Keyword(s):  
Water Vapor ◽  
Chemical Properties ◽  
Urban Site ◽  
Aircraft Measurements ◽  
Raman Lidar ◽  
Lidar System ◽  
Aerosol Composition ◽  
Microphysical Properties ◽  
Multi Wavelength

Abstract. A novel procedure has been developed to retrieve, simultaneously, the optical, microphysical and chemical properties of tropospheric aerosols with a multi-wavelength Raman lidar system in the troposphere over an urban site (Athens, Greece: 37.9° N, 23.6° E, 200 m a.s.l.) using data obtained during the European Space Agency (ESA) THERMOPOLIS project, which took place between 15–31 July 2009 over the Greater Athens Area (GAA). We selected to apply our procedure for a case study of intense aerosol layers that occurred on 20–21 July 2009. The National Technical University of Athens (NTUA) EOLE 6-wavelength Raman lidar system has been used to provide the vertical profiles of the optical properties of aerosols (extinction and backscatter coefficients, lidar ratio) and the water vapor mixing ratio. An inversion algorithm was used to derive the mean aerosol microphysical properties (mean effective radius (reff), single-scattering albedo ω) and mean complex refractive index (m)) at selected heights in the 2–3 km height region. We found that reff was 0.14–0.4 (±0.14) μm, ω was 0.63–0.88 (±0.08) (at 532 nm) and m ranged from 1.44 (±0.10) + 0.01 (±0.01)i to 1.55 (±0.12) + 0.06 (±0.02)i, in good agreement (only for the reff values) with in situ aircraft measurements. The water vapor and temperature profiles were incorporated into the ISORROPIA II model to propose a possible in situ aerosol composition consistent with the retrieved m and ω values. The retrieved aerosol chemical composition in the 2–3 km height region gave a variable range of sulfate (0–60%) and organic carbon (OC) content (0–50%), although the OC content increased (up to 50%) and the sulfate content dropped (up to 30%) around 3 km height; the retrieved low ω value (0.63), indicates the presence of absorbing biomass burning smoke mixed with urban haze. Finally, the retrieved aerosol microphysical properties were compared with column-integrated sun photometer CIMEL data.

Raman lidar system for the measurement of water vapor and aerosols in the Earth’s atmosphere

1992 ◽  
Vol 31 (16) ◽  
pp. 3068 ◽  
Author(s):  
D. N. Whiteman ◽  
S. H. Melfi ◽  
R. A. Ferrare
Keyword(s):  
Water Vapor ◽  
Raman Lidar ◽  
Lidar System ◽  
Earth’S Atmosphere ◽  
Earth's Atmosphere

A Laboratory Study for a Resonance Raman Lidar System

1976 ◽  
Vol 30 (5) ◽  
pp. 528-531 ◽  
Author(s):  
J. G. Hochenbleicher ◽  
W. Kiefer ◽  
J. Brandmüller
Keyword(s):  
Raman Scattering ◽  
Laboratory Study ◽  
Laser Light ◽  
Raman Effect ◽  
Resonance Raman ◽  
Air Pollutant ◽  
Raman Lidar ◽  
Resonance Raman Scattering ◽  
Lidar System ◽  
Remote Analysis

Results of a laboratory study for the applicability of the resonance Raman effect for remote analysis of air pollutant molecules are presented. It was found that the influence of the absorption of the exciting laser light as well as of the scattered resonance Raman light by the scattering gas can reduce the observed resonance signal to normal Raman scattering levels. The laboratory detection limit for continuum resonance Raman scattering of iodine was found to be of the order of 30 ppb.

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