Absolute radiometric calibration with lunar surface reflectance as reference for earth-observing VNIR camera.

Area of Science:

• Remote Sensing
• Earth Observation
• Radiometric Calibration

Background:

• Absolute radiometric accuracy is vital for earth-observing cameras in various applications.
• Existing calibration methods have limitations that necessitate improved approaches.

Purpose of the Study:

• To develop and validate a lunar surface reflectance-based radiometric calibration approach for earth-observing cameras.
• To assess the performance of different lunar models (IIM, M3, SP) for calibration.

Main Methods:

• Utilized lunar calibration sites (MS-2, Apollo-16, CE-3) and lunar reflectance models (IIM, M3, SP).
• Retrieved equivalent lunar reflectance models by integrating with the GF-4 VNIR camera's spectral response function.
• Performed absolute radiometric calibrations across specific spectral bands (520-590nm, 630-690nm, 770-890nm).
• Conducted ground-based validation using targets of varying reflectance and compared results with traditional methods.

Main Results:

• The IIM lunar model demonstrated superior radiometric accuracy compared to other lunar models.
• The SP model showed comparable performance to traditional on-orbit field-based models.
• The lunar-based calibration method proved capable of improving radiometric calibration accuracy.

Conclusions:

• Lunar surface reflectance-based calibration is a viable and effective method for enhancing the radiometric accuracy of earth-observing cameras.
• This approach offers a promising alternative for precise calibration, benefiting applications in natural resources, environment, and agriculture.