[In-Flight Radiometric Calibration for ZY-3 Satellite Multispectral Sensor by Modified Reflectance-Based Method]

Area of Science:

• Remote Sensing
• Geophysics
• Optical Engineering

Context:

• Accurate radiometric calibration is crucial for quantitative remote sensing applications.
• Existing methods for ZY-3 satellite multispectral sensor calibration have limitations.
• In-flight calibration is preferred for maintaining sensor accuracy over time.

Purpose:

• To develop and validate a modified reflectance-based method for ZY-3 satellite multispectral sensor in-flight radiometric calibration.
• To improve the accuracy and reliability of radiometric calibration coefficients.
• To reduce errors associated with image resampling and observation geometry.

Summary:

• A modified reflectance-based method using ZY-3 satellite Level 1A imagery and a geometric model was employed for in-flight radiometric calibration.
• Both two-point and multi-point methods were used, with the multi-point method showing higher accuracy.
• Water calibration sites were identified as a source of significant residual error and filtered out, leading to improved calibration coefficients with relative differences below 2% for the first three bands and below 5% for the last band.

Impact:

• The proposed method provides accurate and reliable radiometric calibration coefficients for the ZY-3 satellite.
• This advancement is valuable for quantitative analysis of multispectral imagery.
• The methodology can be applied to similar satellite missions for improved radiometric calibration.