Ceilometer lidar comparison: backscatter coefficient retrieval and signal-to-noise ratio determination

By Birgit Heese, H. Flentje, Dietrich Althausen, Albert Ansmann, S. Frey. 2010

154 citations recorded by the source corpus.

Abstract. The potential of a new generation of ceilometer instruments for aerosol monitoring has been studied in the Ceilometer Lidar Comparison (CLIC) study. The used ceilometer was developed by Jenoptik, Germany, and is designed to find both thin cirrus clouds at tropopause level and aerosol layers at close ranges during day and night-time. The comparison study was performed to determine up to which altitude the ceilometers are capable to deliver particle backscatter coefficient profiles. For this, the derived ceilometer profiles are compared to simultaneously measured lidar profiles at the same wavelength. The lidar used for the comparison was the multi-wavelengths Raman lidar PollyXT. To demonstrate the capabilities and limits of ceilometers for the derivation of particle backscatter coefficient profiles from their measurements two examples of the comparison results are shown. Two cases, a daytime case with high background noise and a less noisy night-time case, are chosen. In both cases the ceilometer profiles compare well with the lidar profiles in atmospheric structures like aerosol layers or the boundary layer top height. However, the determination of the correct magnitude of the particle backscatter coefficient needs a calibration of the ceilometer data with an independent measurement of the aerosol optical depth by a sun photometer. To characterizes the ceilometers signal performance with increasing altitude a comprehensive signal-to-noise ratio study was performed. During daytime the signal-to-noise ratio is higher than 1 up to 4–5 km depending on the aerosol content. In our night-time case the SNR is higher than 1 even up to 8.5 km, so that also aerosol layers in the upper troposphere had been detected by the ceilometer.

Subfields: Atmospheric Science, Global and Planetary Change

View Paper: https://www.semanticscholar.org/paper/5df50531092ba693a579bdafccc728c342c13217

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Citations in the corpus

An overview of the first decade of Polly NET : an emerging network of automated Raman-polarization lidars for continuous aerosol profiling (2016, background): “The SNR threshold is used to avoid mal-detection due to noise.”
EARLINET: towards an advanced sustainable European aerosol lidar network (2014, background): “They were primarily designed for the height assignment of clouds only, but currently their capability for providing aerosol information is under discussion (Flentje et al., 2010; Heese et al., 2010; Wiegner and Geiß, 2012), in particular after the Eyjafjallajökull eruption in 2010.”