• Geometry: Spherical refractive atmosphere. Nadir, zenith or limb observations. Simple or Combined Upward and Downard trajectories;
• Wide spectral domain : from 100 to 14000 cm-1 ;
• High spectral resolution : the nominal Atlas Processing spectral resolution is 5.10-4 cm-1; Under request, it could be possible to generate special atlases
- latest updates of the line mixing (CO2, CH4, O2). It also includes the line mixing of H2O which has been validated at 6 microns with the IASI observations
• Handling of many types of surface : spectral emissivity, albedos, BRDF/BPDF coming from different sources
• Solar contribution : any available solar spectrum, including the Doppler shift of solar lines at high spectral resolution;
• Scattering : by molecules, aerosols and clouds through DISORT, LIDORT or V-LIDORT; including corresponding jacobians; A faster method (Low Stream Interpolation, O’Dell et al, 2010) has been implemented in 4A/OP
• Polarization is available with V-LIDORT.