Application of a flow through absorption tube for remotely estimating water quality parameters

Abstract

A flow through absorption tube is described and applied. The tube is similar in concept to a 50 cm pathlength cylindrical cuvette described previously by Bostater and Gimond. The new absorption tube allows for continuous, underway measurements of water absorption signatures. Water is allowed to flow through the tube, and in this way the spectral change or track of absorption can be measured as a function of time or space when operated from a stationary or moving platform. Data gathered from various environments ranging from very turbid to clear water is analyzed and described. Concentrations of chlorophyll-a, suspended matter, and dissolved organic matter are quantitatively determined by calculating a double inflection ratio spectra for all combinations of bands from 362-1115 nm using 252 channels as described by Bostater. The absorption tube described here demonstrates the utility of continuous, underway measurements of absorption for estimating concentrations of water quality parameters. ©2004 Copyright SPIE - The International Society for Optical Engineering.