anchor.diff:    SUBROUTINE compute_scatt ( nt, nx, albedo, lat, sza, vza, saa, vaa, l2ctp, l2cfr, terrain_height, amfgeo, &
          amfdiag, scattw)
   
  -    USE OMSAO_lininterpolation_module
       USE OMSAO_variables_module, ONLY: verb_thresh_lev
       USE OMSAO_omidata_module, ONLY: omi_ozone_amount
   
  
positive.code:           ! ----------------------------------------------
            CALL ussa_press(REAL(terrain_height(ixtrack,itimes),KIND=r8) / 1000.0_r8, &
                 local_psurf(ixtrack,itimes) )
            
            clima_psurf = REAL(Psurface(idx_lon, idx_lat), KIND=r8)
            ! lpre(0:CmETA) is pressure at layer boundaries, same unit as
            ! local_surf, convert from hPa to Pa, it is a CmETA+1 = CmEp1 array
            ! Ap(1:CmEp1) & Bp(1:CmEp1) are coeff at layer boundary for pressure
  
negative.code:   ! nt AMF calculations and contains necessary subroutines to read files
    ! and calculate them
    ! ====================================================================
    USE OMSAO_lininterpolation_module
    USE OMSAO_precision_module, ONLY: i4, r8, C_LONG, r4
    USE OMSAO_parameters_module
    USE OMSAO_errstat_module
  