Assessing uncertainties in scattering correction algorithms for reflective tube absorption measurements made with a WET Labs ac-9

Research output: Research - peer-reviewArticle

In situ absorption measurements collected with a WET Labs ac-9 employing a
reflective tube approach were scatter corrected using several possible methods and compared to reference measurements made by a PSICAM to assess performance. Overall, two correction methods performed best for the stations sampled: one using an empirical relationship between the ac-9 and PSICAM to derive the scattering error (ε) in the nearinfrared (NIR), and one where ε was independently derived from concurrent measurements of the volume scattering function (VSF). Application of the VSF-based method may be more universally applicable, although difficult to routinely apply because of the lack of commercially available VSF instrumentation. The performance of the empirical approach is encouraging as it relies only on the ac meter measurement and may be readily applied to historical data, although there are inevitably some inherent assumptions about particle composition that hinder universal applicability. For even the best performing methods, residual errors of 20% or more were commonly observed for many water types. For clear ocean waters, a conventional baseline subtraction with the assumption of negligible near-IR absorption performed as well or better than the above methods because propagated uncertainties were lower than observed with the proportional method.
Original languageEnglish
Pages (from-to)A1139-A1153
Number of pages15
JournalOptics Express
Volume25
Issue number24
DOIs
StatePublished - 10 Nov 2017

    Research areas

  • remote sensing, sensors, absorption, oceanic optics, optical sensing

Bibliographical note

© 2017 Optical Society of America. Users may use, reuse, and build upon the article, or use the article for text or data mining, so long as such uses are for non-commercial purposes and appropriate attribution is maintained. All other rights are reserved.

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