W3FB11

The W3FB11 routine converts the coordinates of a location on earth given in
           the natural coordinate system of latitude/longitude to a grid
           coordinate system overlaid on a Lambert conformal tangent cone
           projection true at a given N or S latitude.

USAGE:  CALL W3FB11 (ALAT,ELON,ALAT1,ELON1,DX,ELONV,ALATAN,XI,XJ)

   InpuT argument list:
      ALAT     - LATITUDE IN DEGREES (NEGATIVE IN SOUTHERN HEMIS)
      ELON     - EAST LONGITUDE IN DEGREES, REAL*4
      ALAT1    - LATITUDE  OF LOWER LEFT POINT OF GRID (POINT (1,1))
      ELON1    - LONGITUDE OF LOWER LEFT POINT OF GRID (POINT (1,1))
                 ALL REAL*4
      DX       - MESH LENGTH OF GRID IN METERS AT TANGENT LATITUDE
      ELONV    - THE ORIENTATION OF THE GRID.  I.E.,
                 THE EAST LONGITUDE VALUE OF THE VERTICAL MERIDIAN
                 WHICH IS PARALLEL TO THE Y-AXIS (OR COLUMNS OF
                 OF THE GRID) ALONG WHICH LATITUDE INCREASES AS
                 THE Y-COORDINATE INCREASES.  REAL*4
                 THIS IS ALSO THE MERIDIAN (ON THE BACK SIDE OF THE
                 TANGENT CONE) ALONG WHICH THE CUT IS MADE TO LAY
                 THE CONE FLAT.
      ALATAN   - THE LATITUDE AT WHICH THE LAMBERT CONE IS TANGENT TO
                 (TOUCHING) THE SPHERICAL EARTH.
                 SET NEGATIVE TO INDICATE A
                 SOUTHERN HEMISPHERE PROJECTION.
 
    Output argument list:
      XI       - I COORDINATE OF THE POINT SPECIFIED BY ALAT, ELON
      XJ       - J COORDINATE OF THE POINT; BOTH REAL*4
 
REMARKS: 
        Formulae and notation loosely based on Hoke, Hayes,
        and Renninger's "Map projections and grid systems...",
        March 1981 AFGWC/TN-79/003

 


  
W3lib.tar
  
Library contains Fortran 90 decoder/encoder
   routines for GRIB edition 1. (Fortran90) 

   Date posted: 2/22/2007