Stray light correction of array spectroradiometers for solar UV measurements

Area of Science:

• Optics and Photonics
• Atmospheric Science
• Radiometry

Background:

• Stray light in spectroradiometers, particularly out-of-spectral range radiation, can significantly distort spectral measurements.
• Solar UV spectroradiometers often have a narrower spectral range than their detectors, making them susceptible to this error.
• Accurate spectral irradiance data is vital for various applications, including atmospheric research and UV exposure monitoring.

Purpose of the Study:

• To develop and demonstrate an approach for characterizing and correcting stray light caused by out-of-spectral range radiation in array spectroradiometers.
• To address the specific challenges of stray light correction in solar UV measurements.
• To evaluate the effectiveness of a hardware solution (bandpass filter) for mitigating out-of-range stray light.

Main Methods:

• Characterization of stray light in two types of solar UV array spectroradiometers.
• Development of a method to correct for out-of-range stray light, requiring knowledge of unmeasured spectral irradiance.
• Implementation and testing of a bandpass filter as a hardware solution for out-of-range stray light reduction.

Main Results:

• The study successfully characterized and corrected stray light in the tested spectroradiometers.
• A method was demonstrated to solve the out-of-range stray light problem for solar UV measurements.
• Test measurements confirmed the effectiveness of the bandpass filter in reducing out-of-range stray light.

Conclusions:

• The presented approach effectively characterizes and corrects stray light in spectroradiometers, enhancing data accuracy.
• The method is particularly beneficial for solar UV measurements where detector spectral ranges exceed instrument capabilities.
• Hardware modifications, such as bandpass filters, offer a viable solution to mitigate out-of-range stray light issues.