A moderate-spectral-resolution transmittance model based on fitting the line-by-line calculation

Area of Science:

• Atmospheric Science
• Radiative Transfer
• Remote Sensing

Background:

• Accurate atmospheric transmittance modeling is crucial for radiative transfer simulations and remote sensing.
• Existing models may lack the computational efficiency required for certain applications.

Purpose of the Study:

• To develop a computationally efficient narrowband transmittance model.
• To ensure the model's accuracy across a wide range of atmospheric conditions and spectral regions.

Main Methods:

• Developed the Fast Fitting Transmittance Model (FFTM) using line-by-line (LBL) calculations.
• Averaged monochromatic transmittances to obtain narrowband transmittances (1 cm⁻¹ intervals).
• Utilized the Curtis-Godson approximation for inhomogeneous atmospheres.

Main Results:

• Created a database of fitting coefficients for arbitrary atmospheric profiles.
• Validated the FFTM against LBLRTM and high-spectral-resolution measurements (AIRS, HIS).
• Achieved a balance between numerical efficiency and accuracy.

Conclusions:

• The FFTM provides an efficient and accurate method for computing moderate- to high-spectral-resolution transmittances.
• FFTM is suitable for radiative transfer simulations and remote sensing.
• The model demonstrates good performance across various pressures and temperatures.