Articles | Volume 9, issue 10
https://doi.org/10.5194/amt-9-4879-2016
https://doi.org/10.5194/amt-9-4879-2016
Research article
 | 
04 Oct 2016
Research article |  | 04 Oct 2016

Estimation of background gas concentration from differential absorption lidar measurements

Peter Harris, Nadia Smith, Valerie Livina, Tom Gardiner, Rod Robinson, and Fabrizio Innocenti

Abstract. Approaches are considered to estimate the background concentration level of a target species in the atmosphere from an analysis of the measured data provided by the National Physical Laboratory's differential absorption lidar (DIAL) system. The estimation of the background concentration level is necessary for an accurate quantification of the concentration level of the target species within a plume, which is the quantity of interest. The focus of the paper is on methodologies for estimating the background concentration level and, in particular, contrasting the assumptions about the functional and statistical models that underpin those methodologies. An approach is described to characterise the noise in the recorded signals, which is necessary for a reliable estimate of the background concentration level. Results for measured data provided by a field measurement are presented, and ideas for future work are discussed.

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Short summary
We have described an approach to estimating the background concentration level of a species, such as methane, in the atmosphere from an analysis of the measured data provided by the National Physical Laboratory's differential absorption lidar (DIAL) system. The estimation of the background level supports the mapping of pollutant concentrations and the determination of emission fluxes. Results for data provided by a field measurement are presented, and ideas for future work are discussed.