Kalman filtering real-time measurements of H2O isotopologue ratios by laser absorption spectroscopy at 2.73 microm.
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.
Wu
Tao
T
Laboratoire de Physicochimie de l'Atmosphère, Université du Littoral Côte d'Opale, 189A Avenue, Maurice Schumann, 59140 Dunkerque, France.
Chen
Weidong
W
Kerstel
Erik
E
Fertein
Eric
E
Gao
Xiaoming
X
Koeth
Johannes
J
Rössner
Karl
K
Brückner
Daniela
D