Characterizations of the mirror attenuator mosaic: solar diffuser plate

Area of Science:

• Earth science
• Radiometry
• Solar calibration

Background:

• The Earth Radiation Budget Experiment (ERBE) requires precise calibration.
• Previous solar diffusers showed instability in orbit.

Purpose of the Study:

• To assess the performance of the Mirror Attenuator Mosaic (MAM) as a solar diffuser for ERBE radiometers.

Main Methods:

• The MAM, featuring vacuum-deposited aluminum mirrors and black chrome, was used for flight calibration.
• Calibration covered broadband shortwave and total spectral ranges.

Main Results:

• The MAM demonstrated effective reflectance stability within +/-2% over nearly two years in orbit.
• This represents a significant improvement compared to earlier solar diffuser technologies.

Conclusions:

• The MAM is a highly stable and effective solar diffuser for calibrating Earth radiation budget instruments.
• Its performance surpasses previous diffuser designs, enhancing data accuracy.