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Updated: Jun 7, 2026
06:27
Measurement of Aerosols Optical Thickness of the Atmosphere using the GLOBE Handheld Sun Photometer
Published on: May 29, 2019
Compact light-emitting-diode sun photometer for atmospheric optical depth measurements
Applied Optics
|November 2, 2010
Summary
A novel light-emitting diode (LED) sun photometer was developed for direct atmospheric optical depth measurement. This new LED sun photometer shows excellent agreement with conventional methods.
Area of Science:
- Atmospheric Science
- Optical Physics
- Instrumentation
Background:
- Accurate measurement of atmospheric optical depth is crucial for climate and air quality monitoring.
- Conventional sun photometers can be complex and expensive.
Purpose of the Study:
- To develop a compact and cost-effective sun photometer using light-emitting diodes (LEDs).
- To validate the performance of the novel LED sun photometer against established methods.
Main Methods:
- A new sun photometer design utilizing an LED as both a spectrally selective photodetector and a nonlinear feedback element.
- Direct measurement of atmospheric optical depths in selected spectral bands by analyzing the output voltage, proportional to the logarithm of solar intensity.
- Comparison of optical depth measurements with a conventional filter photometer.
Main Results:
- The developed LED sun photometer directly measures atmospheric optical depths.
- Measurements showed good agreement (within a few percent) between linear and logarithmic modes of the LED photodetector.
- Optical depth values obtained with the LED sun photometer closely matched those from a conventional filter photometer.
Conclusions:
- The novel LED sun photometer offers a viable and accurate alternative for atmospheric optical depth measurements.
- The compact design and dual-functionality of the LED enhance measurement efficiency and potentially reduce costs.
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