RFM Flags

VRT Flag: Flux-type Calculations Without Solid-angle

Integration
12SEP17

Enabled
Suppress solid-angle integration in flux calculations
Output radiance in [nW/(cm2 sr cm-1)]

Disabled
Flux calculations include solid-angle integration
Output radiance in [W/(m2 cm-1)]

Restrictions
FLX Flag must be enabled
Incompatible with COO Flag.

Notes
  1. The main purpose of this flag is to allow multiple vertical path calculations to different atmosphere levels within the same driver table instead of using different driver tables with the OBS Flag used to set the observer altitude at each level. However, for most purposes, the LEV Flag is simpler to use and more flexible.
  2. Using the VRT Flag to calculate, for example, the (vertical) radiance from the top of the atmosphere down to 25km one could either use
    *FLG
        ZEN RAD OBS ! observer looking upwards at downwelling radiance
    ...
    *TAN
        1.0     ! defines vertical path
    ...
    *OBS
       25.0     ! observer at 25km 
    ...
    *END
    
    or one could get the same answer using
    *FLG
        ZEN RAD FLX VRT ! flux-type calc of downwelling radiance without solid-angle
    ...
    *TAN (or *LEV)
      25.0      ! output at 25km
    ...
    *END
    
    The advantage of the second approach is that multiple output levels can be selected by adding more numbers in the *TAN section

Bugs
Bug#44 (Fixed v4.22)