A generalised background correction algorithm for a Halo Doppler lidar and its application to data from Finland

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http://hdl.handle.net/10138/162998

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Manninen , A J , O'Connor , E J , Vakkari , V & Petäjä , T 2016 , ' A generalised background correction algorithm for a Halo Doppler lidar and its application to data from Finland ' , Atmospheric Measurement Techniques , vol. 9 , no. 2 , pp. 817-827 . https://doi.org/10.5194/amt-9-817-2016

Titel: A generalised background correction algorithm for a Halo Doppler lidar and its application to data from Finland
Författare: Manninen, Antti J.; O'Connor, Ewan J.; Vakkari, Ville; Petäjä, Tuukka
Medarbetare: University of Helsinki, Department of Physics
University of Helsinki, Department of Physics
Datum: 2016
Språk: eng
Sidantal: 11
Tillhör serie: Atmospheric Measurement Techniques
ISSN: 1867-1381
Permanenta länken (URI): http://hdl.handle.net/10138/162998
Abstrakt: Current commercially available Doppler lidars provide an economical and robust solution for measuring vertical and horizontal wind velocities, together with the ability to provide co- and cross-polarised backscatter profiles. The high temporal resolution of these instruments allows turbulent properties to be obtained from studying the variation in radial velocities. However, the instrument specifications mean that certain characteristics, especially the background noise behaviour, become a limiting factor for the instrument sensitivity in regions where the aerosol load is low. Turbulent calculations require an accurate estimate of the contribution from velocity uncertainty estimates, which are directly related to the signal-to-noise ratio. Any bias in the signal-to-noise ratio will propagate through as a bias in turbulent properties. In this paper we present a method to correct for artefacts in the background noise behaviour of commercially available Doppler lidars and reduce the signal-to-noise ratio threshold used to discriminate between noise, and cloud or aerosol signals. We show that, for Doppler lidars operating continuously at a number of locations in Finland, the data availability can be increased by as much as 50% after performing this background correction and subsequent reduction in the threshold. The reduction in bias also greatly improves subsequent calculations of turbulent properties in weak signal regimes.
Subject: AEROSOL DECADAL TRENDS
PRECIPITATION
REGRESSION
STATIONS
HEIGHT
WIND
GAW
114 Physical sciences
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