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Issued patent

OH Detection Using Gas Correlation Radiometry

An issued NASA patent from the Technology Transfer catalog.

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About this technology

Overview

Engineers at NASA’s Goddard Space Flight Center have developed an innovative system to measure hydroxyl (OH) in the atmosphere. Measuring OH is particularly difficult due to its extremely high reactivity and short lifespan, which necessitate active OH generation for use as a reference. However, OH’s reactivity limits the amount that can be generated, and thus additional improvements were required. The solution devised combines properties of Gas Correlation Radiometry (GCR) with Broad-band Cavity Enhanced Absorption Spectroscopy (BBCEAS) to measure OH. GCR is used as a precise bandpass filter to detect OH absorption in the atmosphere, while BBCEAS increases the path length of the cell to make this measurement possible.