*FLG Section

29SEP25

Type
Mandatory Section#2

Description
A series of 3-letter codes indicating various MORSE options to be 'switched on' (all switched off by default)

Format
Multiple 3-character fields of single type, any order, limited set of values.
Field Type Value Description
FLG C3 ACC More stringent default accuracy/convergence criteria[1]
AHY Suppress hydrostatic equilibrium[2]
APR Include A Priori profiles (as an extra SET) in .rtv files
CLD Use cloud detection (see *CLD section)
COL Add integrated column amounts in .rtv files
CTM Use molecular (eg H2O) continuum data (same as RFM Flag)
FGD Use full spectral grid (i.e. override any irregular, grid)
FIX Assume fixed relative altitudes (e.g. detector array)[3]
FMW (MIPAS) Use full microwindow (ie set all masks = TRUE)
FVZ Suppress FOV distortion due to refraction (same as RFM Flag)
GEO Use geometric (ie non-refractive) ray paths (same as RFM Flag)
INF Include information diagnostics in in .rtv files
LIN Assume VMR varies linearly with altitude rather than logarithmically (same as RFM Flag)
MIX Use CO2 line mixing (same as RFM Flag)
MWO Write outputs after each microwindow in .rtv files
QAD Use simple quadratic fit to line wings rather than inverse quadratic (same as RFM Flag)
RES Include vertical resolution factor in .rtv files
RSM Allow run to resume from last pixel

Notes
  1. ACC: Specifically scales the following default settings
    Parameter Default ACC flag
    Convergence Criteria (see *CNV)
    MAXITR 10 ×10
    CHILIM 1.0 ×0.1
    DELCHI 0.1 ×0.1

  2. AHY: This decouples the pressure and temperature profiles so that these are treated as independent.
    • Limb-sounding: retrieved independently without any consideration of altitude spacing
    • Nadir-sounding: use explicit altitude grid for vertical path integrations

  3. FIX: The default is to assume that the individual measurements contributing to a limb scan have some relative pointing uncertainty, so that the height/pressure at each tangent point is an independent unknown. With this flag, it is assumed that the relative heights are fixed, and so the hydrostatic equation can be used to reduce the problem to the tangent height/pressure at a single reference level.

Example