BLL2PS

The BLL2PS routine interpolates a budget-type scalar field from
           a global latitude-longitude cylindrical grid (including the
           poles) to a matched pair of Polar Stereographic grids centered
           on the respective poles, where the orientation longitude
           of the Southern Hemisphere grid is 180 degrees opposite
           that of the Northern Hemisphere grid.  This interpolation
           is designed to approximate an area-average conserving
           interpolation from fine to coarse resolution but to become
           a bilinear interpolation from coarse to fine resolution.
           This is accomplished by bilinearly interpolating to a much
           finer Polar Stereographic grid and then area-averaging to
           the output grid.  The current configuration interpolates
           to an extravagant 121 points in every output grid box.
           This routine also would interpolate associated bitmaps.
           This routine is configured only for (i,j,k) order grids.
           This routine is fully vectorized and multitasked.

USAGE:    CALL BLL2PS(IBM,IM,JM,KM,NPS,KB,TRUE,XMESH,ORIENT,
                      LB,B,LBN,BN,LBS,BS)

   Input argument list:
      IBM      - INTEGER BITMAP IDENTIFIER
                 (0 FOR NO BITMAP, 1 TO INTERPOLATE BITMAP)
      IM       - INTEGER NUMBER OF INPUT LONGITUDES
      JM       - INTEGER NUMBER OF INPUT LATITUDES
      KM       - INTEGER NUMBER OF FIELDS TO INTERPOLATE
      NPS      - INTEGER ODD ORDER OF THE POLAR STEREOGRAPHIC GRIDS
                 (CENTER POINTS ARE THE POLE POINTS)
      KB       - INTEGER SKIP NUMBER BETWEEN INPUT FIELDS
      TRUE     - REAL LATITUDE AT WHICH PS GRID IS TRUE (USUALLY 60.)
      XMESH    - REAL GRID LENGTH AT TRUE LATITUDE (M)
      ORIENT   - REAL LONGITUDE AT BOTTOM OF NORTHERN PS GRID
                 (SOUTHERN PS GRID WILL HAVE OPPOSITE ORIENTATION.)
      LB       - LOGICAL (IM,JM,KM) BITMAP IF IBM=1
      B        - REAL (IM,JM,KM) SCALAR FIELD TO INTERPOLATE

   Output argument list:
      LBN      - LOGICAL (NPS,NPS,KM) NORTHERN PS BITMAP IF IBM=1
      BN       - REAL (IM,JM,KM) INTERPOLATED NORTHERN PS FIELD
      LBN      - LOGICAL (NPS,NPS,KM) SOUTHERN PS BITMAP IF IBM=1
      BN       - REAL (IM,JM,KM) INTERPOLATED SOUTHERN PS FIELD

REMARKS: FORTRAN 90 EXTENSIONS ARE USED.

 


  
SPLIB.tar
  
Library contains routines to be
   be used for a variety of spectral transform functions. (Fortran90) 

   Date posted: 2/23/2007