RFM Flags

VRT Flag: Flux-type Calculations Without Solid-angle


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

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

FLX Flag must be enabled
Incompatible with COO Flag.

  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
        ZEN RAD OBS ! observer looking upwards at downwelling radiance
        1.0     ! defines vertical path
       25.0     ! observer at 25km 
    or one could get the same answer using
        ZEN RAD FLX VRT ! flux-type calc of downwelling radiance without solid-angle
    *TAN (or *LEV)
      25.0      ! output at 25km
    The advantage of the second approach is that multiple output levels can be selected by adding more numbers in the *TAN section

[none recently reported]