anchor.diff:        real, Parameter :: v1=8333., v2=33333. ! frequency cm^-1 bounds
         ! DV: frequency cm^1 step (lower limit 5. per Card 4 p.40)
         real, parameter :: dv=500. 
  +! currently unused variables (don't have to be parameter)
  +      real, parameter :: H2=0. ! only for IEMSCT 1 or 2
  +
   ! Model configuration, see Lowtran manual p. 21(30) s. 3.2
   ! Use only one of the following model scenarios
   
  
positive.code:       integer, parameter :: model=5 ! 5: subarctic winter
        integer, parameter :: itype=3 ! 3: vertical or slant path to space
        integer, parameter :: iemsct=0! 0: transmittance model
  ! in lowtran7.f, I set M1-M6, MDEF all =0 per p.21
  
  !!! Horizontal model (only way to use meterological data) !!!
  
negative.code: !      integer, parameter :: iemsct=0! 0: transmittance model
  ! TODO M1-M6=0 to use JCHAR of card 2C.1 (p.22)
  
  !      real, parameter :: h1 = 0.05  (kilometers altitude of horizontal path)
  !      real, parameter :: angle = 0. ! TODO truthfully it's 90. for horizontal path, have to check/test to see if Lowtran uses this value for model=0
  !-------- END model config -----------------
  
  !-------- array assignments --------
          Real :: TXPy(nwl,ncol), VPy(nwl), ALAMPy(nwl), TRACEPy(nwl),
       &      UNIFPy(nwl), SUMAPy(nwl)
  
          call LWTRN7(Python,nwl,V1,V2,DV,
       &  TXPy,VPy,ALAMPy,TRACEPy,UNIFPy, SUMAPy,
  