LiDAR LILAS

Multi-wavelength LILAS LiDAR Raman at the Laboratory of Atmospheric Optic (LOA).

Keywords : Aerosols, LiDARs, MicroLiDARs, monitoring, Earth observation, remote sensing, Raman, wavelengths, ash, dust, sand.

July 29th 2022

The Laboratoire d’optique atmosphérique (LOA) is a joint research unit of the National Center for Scientific Research (CNRS) of France and the University of Lille – Sciences and Technologies. The LOA studies the different components of the atmosphere, mainly clouds, aerosols and gas. In collaboration with the LOA, CIMEL created a joint research laboratory : AGORA-LAB.

Since 2005, the LOA has started the systematic observation of aerosols by LiDAR and has developed a database and an automated real-time data processing system. Its collaboration with CIMEL allowed the creation of the multi-wavelength LILAS LiDAR which was integrated into the European network EARLINET/ACTRIS in 2015.

The LILAS LiDAR was specifically designed and adjusted by CIMEL to meet a specific need of the LOA. The transportable multi-wavelength Raman research LiDAR LILAS offers a significant qualitative and quantitative value on aerosol parameters measured at night and during the day, in particular through its combination with CIMEL sun/sky/lunar photometers.

LILAS also allows the observation of clouds and the obtention water vapor and methane profiles. It also gives access to essential climate variables such as the absorption profile of atmospheric aerosols. Its maximum range can reach 20 km and allows it to study the lower stratosphere which can be useful in case of major volcanic eruption for example.

For the Data treatment, the AUSTRAL (AUtomated Server for the TReatment of Atmospheric Lidars) web server data is the processing tool, which provides real-time quicklooks of the LiDAR Range Corrected Signals (RCS) and Volume Depolarization Ratio (VDR) as well as Klett inversion results (extinction and backscatter coefficient profiles).

To answer the need of various stakeholders, the CE710 LiDAR is a fully customizable high power multi-channel aerosols LiDAR resulting from the collaboration between the LOA, CIMEL and Dr. Igor Veselovskii institute. Depending on the requirements and budgets of each, it exists multiple options to customize the LiDAR. For exemple, the choice of the laser type and the wavelengths, the depolarization options or the Raman options (and many more).

Thanks to its precision in the detection of aerosols, the LILAS CE710 LiDAR has highlighted many atmospheric natural events such as volcanic eruptions (ash) or dust and sand events for example but also biomass burning particles coming from fires. LILAS data and all the LiDAR’s activities between the LOA and CIMEL bring a precious monitoring tool to understand atmospheric phenomenas over France, Europe and worldwide.


Figure 1 : View of LILAS (telescope, laser, and acquisition bay) in vertical view, open roof hatch and example of observed aerosol profiles. LILAS is a transportable multi-wavelength Elastic & Raman LiDAR. It has 3 elastic channels (355, 532 and 1064 nm), 3 Raman channels (387, 407 and 530 nm) and 3 depolarized channels (355, 532 and 1064 nm).

Figure 2: Night time LILAS operation during SHADOW-2 campaign in Senegal (Credits: Q. Hu, LOA)

Figure 3 : Detection of smoke particles injected up to 17 km into the stratosphere by intense pyro-convection generated by the Canadian wildfires of summer 2017 (Hu et al., 2018).

Figure 4: Illustration of the extreme event in October 2017. LiDAR LILAS time series from 16/10/17-16:00 to 17/10/17-06:00 UTC at the Lille site (LOA). (a) The reddest regions indicate a high concentration of particles while the blue regions indicate a very low concentration of particles. (b) Aerosol depolarization which informs us about the shape of the particles and thus their nature, desert or fire particles.
 Graphic credits Q. Hu, LOA

Figure 5: LiDAR LILAS LOA
Communications and posters
  • Podvin T., P. Goloub, D. Tanré, I. Veselovskii, V. Bovchaliuk, M. Korensky, A. Mortier, S. Victori, .LILAS, un LIDAR multispectral et Raman pour l’étude des aérosols, de la vapeur d’eau et des nuages, Atelier Experimentation et Instrumentation 2014 (oral presentation)
  • Podvin T, Q. Hu, P. Goloub,  O. Dubovik, I. Veselovskii, V. Bovchaliuk, A. Lopatin, B. Torres, D. Tanré, C. Deroo, T. Lapyonok, F. Ducos, A. Diallo. , LILAS, le Lidar multi spectral Raman polarisé et quelques résultats d’inversions, Atelier Experimentation et Instrumentation 2017 (poster presentation).
  • Hu et al., Aerosol absorption measurements and retrievals in SHADOW2 campaign, ICAC 2017, International Conference on Aerosol Cycle, 21 – 23 Mar, Lille
  • Hu et al., A test of new approaches to retrieve aerosol properties from Photometer-LiDAR joint measurements, ESA/IDEAS Workshop 2017, Lille, 06-07 Apr 2017
  • Hu et al., Retrieval of aerosol properties with Sun/Sky-photometer and LiDAR measurements, ACTRIS-FR, Workshop, Autrans Méaudre en Vercors, 3-5 mai 2017
  • Hu et al., Retrieval of aerosol properties with Sun/Sky-photometer and LiDAR measurements, 28th ILRC, international LiDAR and Radar conference, Bucharest, 25 – 30 June
  • Hu et al., Lidar measurements with 3-depolarization in Lille, 3rd ACTRIS-2 WP2 Workshop, Delft, 13-17 Nov 2017.

Méteo France

METEO-FRANCE network of CIMEL’s instruments

Keywords : Aerosols, LiDARs, monitoring, Earth observation, remote sensing, CAL/VAL, atmosphere, air quality, photometers, aviation, volcanos survey, volcanic ashes, atmospheric monitoring

July 06th 2022

Météo-France is a public administrative institution, the official meteorological and climatological service in France. As such, it exercises the State’s responsibilities in terms of meteorological safety. The institution is also in charge of managing and modernizing an observation network of the atmosphere, the surface ocean and the snow cover in France and overseas.

The institution is also present on an international level as it contributes to the programs and activities of the World Meteorological Organization (WMO) which sets standards that meet the shared needs of its Member States.

Météo-France’s research department, the Centre national de recherches météorologiques (CNRM), is a joint research unit with the CNRS. Météo-France is also a joint supervisor of the Laboratoire de l’Atmosphère et des CYclones (LaCy), the Service des Avions Français Instrumentés pour la Recherche et l’Environnement (SAFIRE), and the Observatoire Midi-Pyrénées (OMP).

Météo-France core missions are linked to the needs related to the protection of people and property: weather forecasting, knowledge of the climate and its evolution, physics and dynamics of the atmosphere and interactions between men, the climate and the atmosphere…

The knowledge of weather conditions is of huge importance for the aviation industry for example. Landing, taking off and even flying safely depends on weather conditions. The perfect example of this huge importance is the eruption of the volcano Eyjafjallajökull which occurred in April 2010. The Icelandic volcano released a thick ash of smoke which disrupted European air traffic, causing five days of complete interruption of traffic: the largest closure of airspace decreed in Europe, not without financial consequences as it led to considerable losses.

Indeed, volcanic ash which tends to settle in the atmosphere is dangerous as it can be sucked into the plane’s engines, then, melt, and finally clog the jet engines. It can cause air plane accidents.

Hence the importance of using state-of-the-art remote sensing measuring instruments to determine for instance the localization, the characterization and the concentration of aerosols in the atmosphere. For this purpose, Météo-France works in collaboration with the LOA (Laboratoire d’Optique Atmosphérique) to manage and maintain a network of efficient solutions and link several instruments such as LiDARs and CIMEL photometers (ready-to-use by AERONET) for more accurate data and considerably reduced uncertainties.

To this end, CIMEL works in close collaboration with Météo-France and ensures to provide quality and constantly improved instruments to meet the urgent needs in terms of security.

Actually, CIMEL also provides instrument synergies between Photometers and LiDARs through a unique monitoring software iAAMS, dedicated to the aerosols study and analysis. The obtained parameters are the characterization of aerosol types, the extinction and backscatter profile of mass concentration. Cimel’s AAMS is able to automatically locate, identify and quantify aerosols, layer by layer, day and night.

Sunbelt Spectra comparison with Standard ASTM G173: the Chilean case

Sunbelt Spectra comparison with Standard ASTM G173: the Chilean case

December, 2017

Two spectra of solar direct normal irradiance (including circumsolar) are estimated based on spatio-temporal averages of the relevant atmospheric parameters extracted from two different databases: MODIS satellite sensor retrievals and AERONET sun photometer network. The satellite database is used to calculate an average spectrum for the area of the Atacama Desert. The AERONET database is used for two purposes: (i) to apply bias-removal linear methods to correct the MODIS parameters over Atacama, and (ii) to calculate an average local spectrum for the Paranal station. The SMARTS radiative transfer model is used to obtain the three spectra developed in this study. Both the Atacama and Paranal spectra are compared against each other and also to the world reference, ASTM G173. In one of the cases, significant differences are found for short wavelengths. In order to quantify the relative importance of these spectral differences, the propagation of errors due to the use of each spectrum is evaluated for CSP applications over the Atacama Desert, considering twelve different scenarios involving the reflectance, transmittance or absorptance of various materials.

Citation: Marzo, Aitor & Polo, Jesus & Wilbert, Stefan & Gueymard, Chris & Jessen, Wilko & Ferrada, Pablo & Alonso-Montesinos, Joaquín & Ballestrín, Jesús. (2017). Sunbelt Spectra comparison with Standard ASTM G173: the Chilean case. AIP Conference Proceedings. 2033. 10.1063/1.5067195.

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