title: Kalman filtering real-time measurements of H2O isotopologue ratios by laser absorption spectroscopy at 2.73 microm.
abstract: Kalman adaptive filtering was applied for the first time, to our knowledge, to the real-time simultaneous determination of water isotopic ratios using laser absorption spectroscopy at 2.73 microm. Measurements of the oxygen and hydrogen isotopologue ratios delta(18)O, delta(17)O, and delta(2)H in water showed a 1-sigma precision of 0.72 per thousand for delta(18)O, 0.48 per thousand for delta(17)O, and 0.84 per thousand for delta(2)H, while sampling the output of the tuned Kalman filter at 1 s time intervals. Using a standard running average technique, averaging over approximately 30 s is required to obtain the same level of precision.
authors.affiliation: Laboratoire de Physicochimie de l'Atmosphère, Université du Littoral Côte d'Opale, 189A Avenue, Maurice Schumann, 59140 Dunkerque, France.
authors.forename: Tao
authors.initials: T
authors.lastname: Wu
authors.forename: Weidong
authors.initials: W
authors.lastname: Chen
authors.forename: Erik
authors.initials: E
authors.lastname: Kerstel
authors.forename: Eric
authors.initials: E
authors.lastname: Fertein
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Gao
authors.forename: Johannes
authors.initials: J
authors.lastname: Koeth
authors.forename: Karl
authors.initials: K
authors.lastname: Rössner
authors.forename: Daniela
authors.initials: D
authors.lastname: Brückner