program read_QuikScat
c
c	Peter M. Woiceshyn	August 23, 2002
c       818-354-1450
c	Peter.M.Woiceshyn@jpl.nasa.gov
c
c   Sample program provides read statements to read in QuikScat SeaWinds
C       scatterometer data of wind speed (meters/second) and wind direction
c       using the oceanographic convention for direction (for example,
C	wind towards the north is 0 degrees, towards the east it is 90, 
C	degrees, towards the south it is 180 degrees, and towards the
C	west it is 270 degrees.
c
c   The wind speed data are on a 1440 X 720 element grid with the origin
c       at -89.875 South latitude and 0.125 degrees East longitude (i.e.,
C       a 0.25 by 0.25 degree lat/lon grid resolution ranging from -89.875
C       (S) to 89.875 (N) in latitude & from 0.125 to 359.875 in East
C       longitude).  A NUMspd array accompanies the spd array ... a value
C       of 1 indicates good data and a value of 0 indicates no data for 
C       the grid point in the spd array
c
c   The wind direction data are on a 72 X 36 element grid with the origin
c       at -88.75 South latitude and 1.25 degrees East longitude (i.e.,
C       a five by five degree lat/lon grid resolution ranging from
C       -88.75 (S) to 86.25 (N) in latitude & from 1.25 to 356.25 in
C       East longitude).  The wind direction data, however, have been
c	computed on the basis of a 2.5 by 2.5 lat/lon degree average at
c	each grid point for each month. A NUMdir array accompanies the
c       dir array ... a value of 1 indicates good data and a value of 0 
c       indicates no data for the grid point in the direction array

c
c   There are 12 months of data for the year 2000.
c
c   Note that the data for each month corresponds
c        to a calender month.
c
c  Declarations:

	REAL del1, del2
        REAL spd(1440,720), NUMspd(1440,720)
        REAL dir(72,36), NUMdir(72,36)
	REAL lon2(1440), lat2(720)
	REAL lon1(72)  , lat1(36)
C	
	INTEGER*2 nlon1, nlat1, nlon2, nlat2
c
	
	CHARACTER*3  c_mon(12)
	CHARACTER*2  yc, mc(12)
	CHARACTER*20 f_in
	CHARACTER*5  f_label
	CHARACTER*4  suff, f_ycmc

C----------------------------------------------------------------------C

	DATA   c_mon/'Jan','Feb','Mar','Apr','May','Jun',
     &	              'Jul','Aug','Sep','Oct','Nov','Dec'/

	DATA  mc/'01','02','03','04','05','06',
     &	         '07','08','09','10','11','12'/


C----------------------------------------------------------------------C

	     yc = '00'
	
	   suff = '.dat'

        f_label = c_mon(1)//yc	! Jan00
         f_ycmc = yc//mc(1)
  
           f_in = 'QuikScat'//f_ycmc//suff
	   PRINT *,' ' 
	   PRINT *,'    '//f_in//'    '//f_label

C----------------------------------------------------------------------C

	     nlon1 =   72
	     nlat1 =   36
  
	     nlon2 = 1440
	     nlat2 =  720
  
	     del1 = 5.0
	     del2 = 0.25
  
	   PRINT *,' ' 
	   PRINT *,'    longitude array dimension for spd =  ',nlon2
	   PRINT *,'     latitude array dimension for spd =  ',nlat2
	   PRINT *,'            delta lat/lon deg for spd = ',del2
	   PRINT *,' ' 

	   PRINT *,'    longitude array dimension for dir =  ',nlon1
	   PRINT *,'     latitude array dimension for dir =  ',nlat1
	   PRINT *,'            delta lat/lon deg for dir = ',del1
	   PRINT *,' ' 

C----------------------------------------------------------------------C
C  Construct lat & lon arrays for speed

	  DO jj = 0, nlat2 - 1
	
                   lat2(jj+1) = jj*del2 - 90.0 + del2/2.0
		   
ccc		IF (jj .LT. 6) PRINT *, '   lat2 = ',lat2(jj+1)

	  END do

	  DO ii = 0, nlon2 - 1
	
                   lon2(ii+1) = ii*del2 + del2/2.0
	  END do
  
C  Construct lat & lon arrays for direction

	  DO jj = 0, nlat1 - 1
	
                   lat1(jj+1) = jj*del1 - 90.0 + 1.25

ccc		IF (jj .LT. 6) PRINT *, '   lat1 = ',lat1(jj+1)
	  END do

	  DO ii = 0, nlon1 - 1
	
                   lon1(ii+1) = ii*del1 + 1.25
	  END do
C----------------------------------------------------------------------C
  
c	FOR SPEED
c
c	Lat range:	-89.875(S) to  89.875(N) degrees 
c
c	Lon range:	  0.125E)  to 359.875(E) degrees 
c
c
c	FOR DIRECTION
c
c	Lat range:	-88.75(S) to  88.75(N) degrees 
c
c	Lon range:	  1.25(E) to 358.75(E) degrees 
c
c
	   PRINT *,' ' 
	   PRINT *,'    Reading file: ',f_in
	   PRINT *,' ' 

	       OPEN(22,file=f_in,form='unformatted')

		      read(22) spd
		      read(22) NUMspd
		      read(22) dir
		      read(22) NUMdir
	
	       CLOSE(22)
	       
	   PRINT *,' ' 
	   PRINT *,' 		Sample Wind Speed Data:' 
	   PRINT *,' ' 

	DO j = 270, 271
	     DO i = 1, 5

	   WRITE (6,'(A5,I1,2x,A5,I3,2x,A6,F6.2,2X,A6,F4.2,2X,A6,
     &            F4.2,2x,A6,F3.1)') 
     &       ' i = ', i,' j = ', j,
     &       'lat = ', lat2(j),'lon = ', lon2(i),
     &          'spd = ',spd(i,j),'Num = ', 
     &        NUMspd(i,j)
	       
	     END DO
	        WRITE (6,'(A2)') ' ' 
	END DO

	        WRITE (6,'(A2)') ' ' 

	   PRINT *,' 		Sample Wind Direction Data:' 
	   PRINT *,' ' 

	DO j = 18, 19
	     DO i = 1, 5

	  WRITE (6,'(A5,I1,2x,A5,I3,2x,A6,F5.2,2X,A6,F5.2,
     &          2X,A6,F6.2,2x,A6,F3.1)') 
     &       'i = ', i,'j = ', j,
     &       'lat = ', lat1(j),'lon = ', lon1(i),
     &       'dir = ', dir(i,j),
     &       'Num = ', NUMdir(i,j)
	       
	     END DO
	        WRITE (6,'(A2)') ' ' 
	END DO
	        WRITE (6,'(A2)') ' ' 
C----------------------------------------------------------------------C
	       
	STOP

	END

C----------------------------------------------------------------------C
C
C  Output from executing this program:
C
c host{pw}432> read_QkScat.x
c 
c    QuikScat0001.dat        Jan00
c  
c     longitude array dimension for spd =    1440
c      latitude array dimension for spd =    720
c             delta lat/lon deg for spd =    0.250000
c  
c     longitude array dimension for dir =    72
c      latitude array dimension for dir =    36
c             delta lat/lon deg for dir =     5.00000
c  
c  
c     Reading file: QuikScat0001.dat    
c  
c  
c                Sample Wind Speed Data:
c
c i = 1   j = 270  lat = -22.62  lon = 0.12  spd = 6.34  Num = 1.0
c i = 2   j = 270  lat = -22.62  lon = 0.38  spd = 6.24  Num = 1.0
c i = 3   j = 270  lat = -22.62  lon = 0.62  spd = 6.43  Num = 1.0
c i = 4   j = 270  lat = -22.62  lon = 0.88  spd = 6.62  Num = 1.0
c i = 5   j = 270  lat = -22.62  lon = 1.12  spd = 6.79  Num = 1.0
c  
c i = 1   j = 271  lat = -22.38  lon = 0.12  spd = 6.27  Num = 1.0
c i = 2   j = 271  lat = -22.38  lon = 0.38  spd = 6.28  Num = 1.0
c i = 3   j = 271  lat = -22.38  lon = 0.62  spd = 6.46  Num = 1.0
c i = 4   j = 271  lat = -22.38  lon = 0.88  spd = 6.53  Num = 1.0
c i = 5   j = 271  lat = -22.38  lon = 1.12  spd = 6.76  Num = 1.0
c  
c   
c                Sample Wind Direction Data:
c  
c i = 1   j =  18  lat = -3.75  lon =  1.25  dir = 352.17  Num = 1.0
c i = 2   j =  18  lat = -3.75  lon =  6.25  dir =   7.32  Num = 1.0
c i = 3   j =  18  lat = -3.75  lon = 11.25  dir =   2.66  Num = 1.0
c i = 4   j =  18  lat = -3.75  lon = 16.25  dir =   0.00  Num = 0.0
c i = 5   j =  18  lat = -3.75  lon = 21.25  dir =   0.00  Num = 0.0
c  
c i = 1   j =  19  lat =  1.25  lon =  1.25  dir =  19.28  Num = 1.0
c i = 2   j =  19  lat =  1.25  lon =  6.25  dir =  34.10  Num = 1.0
c i = 3   j =  19  lat =  1.25  lon = 11.25  dir =   0.00  Num = 0.0
c i = 4   j =  19  lat =  1.25  lon = 16.25  dir =   0.00  Num = 0.0
c i = 5   j =  19  lat =  1.25  lon = 21.25  dir =   0.00  Num = 0.0
c  
c  
C host{wd21pw}433> 
C
C----------------------------------------------------------------------C