onwards: divide user-supplied layers into two (by altitude)
Limit thickness of vertical layers to comply with maximum allowed
variation of Planck Function and line width.
profile points until criteria are met, retaining all
original profile points.
Use vertical profile levels as specified in the *HGT profile
the first .atm file in the
*ATM section of the
The main purpose of this flag is as a quick test to see if the
altitude grid-spacing on the user-supplied profiles
is sufficiently fine to support the assumptions
used in equating atmospheric paths to equivalent homogeneous paths for
the Curtis-Godson approximation and Planck-function variation
(see also BFX flag for Planck-variation).
If the results with/without the LAY flag are significantly different
then the layering is too coarse.
The PRF Flag can be used to write out
the new profiles that are actually used