Real-time radiometric correction method and apparatus for spectral reflectance

A real-time radiometric correction apparatus for a spectral reflectance, comprising:

• a photosynthetically active irradiance obtaining module configured to obtain a photosynthetically active irradiance measured by a photosynthetically active radiation sensor, wherein the photosynthetically active radiation sensor comprises a cosine corrector;
• a photosynthetically active irradiance calculation module configured to obtain a photosynthetically active irradiance of a target band based on a proportional relationship between the photosynthetically active irradiance and a downwelling solar irradiance within a same wavelength range, wherein the downwelling solar irradiance is obtained based on a standard solar spectral irradiance model, the target band is any band in a spectral band obtained by an imaging hyperspectral sensor, and an imaging time point of the imaging hyperspectral sensor is synchronized with a measurement time point of the photosynthetically active radiation sensor;
• and
• wherein the photosynthetically active irradiance calculation module obtains the photosynthetically active irradiance of the target band based on the proportional relationship between the photosynthetically active irradiance and the downwelling solar irradiance within the same wavelength range by:
• calculating a first total value of the photosynthetically active irradiance and a second total value of the downwelling solar irradiance within the same wavelength range;
• calculating a ratio of the first total value to the second total value;
• and
• calculating a product of the ratio and downwelling solar irradiance of the target band to obtain the photosynthetically active irradiance of the target band;
• a photosynthetically active irradiance adjustment module configured to perform a weighted adjustment on the photosynthetically active irradiance of the target band to obtain a corrected target irradiance of the target band;
• wherein the step of performing the weighted adjustment on the photosynthetically active irradiance of the target band to obtain the corrected target irradiance of the target band comprises:
• within a wavelength range of the imaging hyperspectral sensor, performing the weighted adjustment on the photosynthetically active irradiance of the target band by using a spectral response function of the imaging hyperspectral sensor, to obtain the corrected target irradiance of the target band.