High-accuracy Atmosphere Correction for Hyperspectral Data (hatch)

1) the Malkmus band model based on HITRAN 92 database: HITRAN 96 and HITRAN 99 are now available with more accurate molecular line parameters. Also ATREM employs the multiplication rule to handle transmittance in spectral regions where multiple gas absorption is present. This results in less accurate transmittance calculation in these regions, e.g., at 2.0μm where both H2O and CO2 strongly absorb. 2) separation of multiple scattering process from absorption process in the atmosphere: this is a result from the use of a band model for gaseous transmittance calculation. It causes less accurate path radiance calculation for short wavelengths and for turbid atmospheric conditions. 3) the three-band ratioing technique for water vapor amount retrieval: the prerequisite for this technique is that the surface reflectance spectrum is linear in wavelength in the water vapor absorption region to be used. This brings about retrieval errors when the surface reflectance spectrum is not linear for wavelength, for instance, for iron rich soil and wet vegetation.