Spectroradiometer Calibration for Radiance Transfer Measurements.

Area of Science:

• Optical remote sensing
• Radiometric calibration
• Earth observation

Background:

• Integrating spheres provide broadband emission for radiometric calibration.
• Spectroradiometers link integrating sphere radiance to SI-traceable standards.
• Accurate calibration is vital for Earth observation instruments.

Purpose of the Study:

• To calibrate a Spectra Vista Corporation (SVC) HR-1024i spectroradiometer.
• To enable radiance transfer measurements at the Calibration Home Base (CHB).
• To support imaging spectrometers at the German Aerospace Center (DLR).

Main Methods:

• Spectral and radiometric response calibration of the SVC HR-1024i spectroradiometer.
• Measurement of non-linearity, temperature sensitivity, and polarized light effects.
• Radiance transfer measurements using the calibrated spectroradiometer.

Main Results:

• Achieved relative expanded uncertainties between 1% and 3% (k=2).
• Covered the wavelength range of 380 nm to 2500 nm.
• Uncertainties were primarily limited by the radiance standard.

Conclusions:

• The calibrated spectroradiometer enables accurate radiance transfer measurements.
• This work supports precise radiometric calibration for remote sensing applications.
• Further improvements in radiance standards are needed to reduce overall uncertainties.