Viewing and geometric configuration

The plan-parallel atmosphere assumption has been replaced by a spherical atmosphere approximation. This has been obtained by a simple vectorisation of the incidence and observation angles which are now calculated for each layer by a simple trigonometric correction.

Figures below describe the viewing configurations.

Earth viewing configurations :

Viewing with ground surface reflexion (TRAJET=DOWNUP)
Viewing with cloud reflexion (TRAJET=UPDOWN)
Nadir viewing (TRAJET=UP)
Zenith viewing (TRAJET=DOWN)

Limb viewing configurations :

Limb view through the tangent point (TRAJET = DOWNUP)
Limb view of a cloud top, including reflection of downward terrestrial and solar radiation (TRAJET = DOWNUP)
Limb view of a cloud top (TRAJET = UP)
Backward limb view of a cloud bottom, including reflection of upward terrestrial radiation (TRAJET = UPDOWN)
Backward limb view of sky or a cloud bottom (TRAJET = DOWN)