**W3FB04**
The **W3FB04** routine converts the coordinates of a location on
earth from the natural coordinate system of
latitude/longitude to the grid (i,j) coordinate
system overlaid on a polar stereographic map
projection true at 60 degrees n or s latitude.
USAGE: CALL W3FB04 (ALAT, ALONG, XMESHL, ORIENT, XI, XJ)
Input variables:
ALAT LATITUDE IN DEGREES (<0 IF SH)
ALONG WEST LONGITUDE IN DEGREES
XMESHL MESH LENGTH OF GRID IN KM AT 60 DEG LAT(<0 IF SH)
(190.5 LFM GRID, 381.0 NH PE GRID,-381.0 SH PE GRID)
ORIENT ORIENTATION WEST LONGITUDE OF THE GRID
(105.0 LFM GRID, 80.0 NH PE GRID, 260.0 SH PE GRID)
Output variables:
XI I OF THE POINT RELATIVE TO NORTH OR SOUTH POLE
XJ J OF THE POINT RELATIVE TO NORTH OR SOUTH POLE
REMARKS:
All parameters in the calling statement must be real.
The range of allowable latitudes is from a pole to 30
degrees into the opposite hemisphere. The grid used in
this subroutine has its origin (i=0,j=0) at the pole in
either hemisphere, so if the user's grid has its
origin at a point other than the pole, a translation is
needed to get i and j. The gridlines of i=constant are
parallel to a longitude designated by the user.
The earth's radius is taken to be 6371.2 km.
WARNING:
This code is not vectorized. You will have put
it line to vectorize it.
W3lib.tar |
Library contains Fortran 90 decoder/encoder
routines for GRIB edition 1. (Fortran90)
Date posted: 2/22/2007 |