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Updated: Jun 12, 2026
10:08
High-Throughput Analysis of Non-Photochemical Quenching in Crops Using Pulse Amplitude Modulated Chlorophyll Fluorometry
Published on: July 6, 2022
Summary
A novel photometer precisely measures faint daytime thermospheric emissions, overcoming background noise. This breakthrough enables new studies of atmospheric phenomena like dayglow.
Area of Science:
- Atmospheric Physics
- Optical Instrumentation
- Aeronomy
Background:
- Measuring faint atmospheric emissions against bright solar backgrounds is challenging.
- Previous attempts to measure daytime thermospheric emissions faced significant limitations.
Purpose of the Study:
- To develop and commission a unique photometer for measuring daytime oxygen (OI) 630.0-nm emissions in the thermosphere.
- To overcome the limitations of prior instruments in detecting low-intensity signals.
Main Methods:
- Utilized a low-resolution (10^4) Fabry-Perot etalon.
- Incorporated a temperature-tuned, narrowband (3-Å) interference filter.
- Employed a radial chopper and an up/down counting system for background elimination.
Main Results:
- Successfully developed and commissioned a photometer capable of measuring line intensities below 0.1% of the background continuum.
- Demonstrated the ability to measure daytime OI 630.0-nm emission from the thermosphere.
Conclusions:
- The developed photometer overcomes previous measurement limitations for faint atmospheric phenomena.
- The instrument's design and background elimination method open possibilities for various applications beyond current dayglow studies.
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