Articles | Volume 18, issue 11
https://doi.org/10.5194/amt-18-2537-2025
https://doi.org/10.5194/amt-18-2537-2025
Research article
 | 
16 Jun 2025
Research article |  | 16 Jun 2025

On path length, beam divergence, and retroreflector array size in open-path FTIR spectroscopy

Cameron E. N. Power and Aldona Wiacek

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Cited articles

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Short summary
The choice of path length and retroreflector array size in open-path Fourier transform infrared spectroscopy must be made with care.  Longer paths increase target gas absorption (lowering detection limits), and larger retroreflector arrays increase the return signal (improving retrieved concentration precision), but there are limitations to both. An optimum array size and path combination exists in each specific observational environment and application, as explored in this work.
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