Instrumentation for remote sensing solar radiation from light aircraft

Area of Science:

• Earth and Space Sciences
• Atmospheric Science
• Remote Sensing

Background:

• Studying ground surface solar radiation and albedo is crucial for understanding Earth's energy balance.
• Aircraft-based measurements offer a unique perspective for large-scale albedo assessments.
• Previous methods may have limitations in capturing spectral or directional albedo variations.

Purpose of the Study:

• To describe the specialized instrumentation for airborne measurement of incoming and reflected solar radiation.
• To evaluate the performance of different pyranometer types (narrow-beam vs. global) for albedo determination.
• To compare airborne albedo measurements with ground-based data.

Main Methods:

• Utilized a light aircraft equipped with a global shortwave radiometer on the roof.
• Mounted a downward-pointing aerial camera, narrow-beam pyranometer, and global shortwave pyranometer.
• Calibrated pyranometers against a standard Angstrom compensation pyrheliometer.

Main Results:

• Determined calibration factors for airborne pyranometers.
• Observed distinct albedo trends for major plant communities.
• Calculated albedo values differed significantly based on whether a narrow-beam or global sensor was used.
• Found good agreement between airborne and ground-measured albedos.

Conclusions:

• The developed airborne instrumentation is effective for studying surface albedo.
• The choice of downward-pointing radiometer significantly impacts albedo measurements.
• Airborne remote sensing provides valuable data for characterizing vegetation albedo across landscapes.