CALL SEQUENCE...
       delhat  PHIS PHI DEL OUTPUT
 
 
      DESCRIPTION...
       delhato - COMPUTES DELTA-HAT FROM OBSERVED HEIGHTS
 
 
      AUTHOR   - J.D.Henderson, NOV 24/81.
      LAST REVISION: $Header: /home/cvs/RMNLIB/utils/rdiag/lspgm/delhato.ptn,v 4.10 2014/09/25 20:20:46 dugas Exp $
 
 
      PURPOSE  - COMPUTES DELTA-HAT FOR SETS OF GEOPOTENTIAL PHI AND SURFACE
                 GEOPOTENTIAL PHIS. DELTA-HAT IS 1.0 AT EVERY POINT ABOVE THE 
                 MOUNTAIN(S) AND 0.0 BELOW IT.
                    
 
      INPUT FILES...
       PHIS = SURFACE GEOPOTENTIAL FIELD
       PHI  = GEOPOTENTIAL HEIGHTS GRID SETS ON PRESSURE LEVEL
 
      OUTPUT FILE...
       DEL  = OUTPUT SET OF THE DELTA-HAT FUNCTION
 
 
      EXIT CONDITIONS...
        0 NO PROBLEMS
        1 UNABLE TO READ MONTAIN FILE
        2 PREMATURE EOF ON GEOPOTENTIAL FILE 
        3 MONTAINS AND GEOPOTENTIAL NOT THE SAME SIZE
        4 FOUND WRONG VARIABLES
        5 VERTICAL COORDINATE IS NOT PRESSURE