Radiometric Calibration for a Multispectral Sensor Onboard RISESAT Microsatellite Based on Lunar Observations

Area of Science:

• Remote Sensing
• Optical Sensor Calibration
• Satellite Technology

Background:

• Radiometric calibration is crucial for satellite optical sensor performance evaluation.
• Lunar calibration offers a cost-effective, equipment-free method suitable for nanosatellites.
• Assessing sensor performance degradation and trends is vital for data accuracy.

Purpose of the Study:

• To apply lunar calibration to the Ocean Observation Camera (OOC) multispectral sensor.
• To evaluate sensor sensitivity degradation and identify trends.
• To validate lunar calibration parameters against established datasets.

Main Methods:

• Simulated lunar brightness using RObotic Lunar Observatory and SELENE/Spectrum Profiler models.
• Applied lunar calibration to the OOC sensor onboard the Rapid International Scientific Experiment Satellite.
• Compared top-of-atmosphere reflectance data with the Radiometric Calibration Network dataset.

Main Results:

• Sensor temperature correction demonstrated negligible sensitivity degradation in OOC's four spectral bands.
• A bluing trend was observed, with shorter wavelengths showing higher irradiance.
• Lunar calibration parameters effectively corrected the bluing trend in the visible range.

Conclusions:

• Lunar calibration is a viable method for evaluating microsatellite multispectral sensors like the OOC.
• The study identified and corrected a bluing trend in the sensor's visible spectral bands.
• While infrared band calibration showed inconsistencies, lunar calibration shows potential for estimating background radiance.