c Template of a program that uses the instrument data routines & data files.

c Declarations

      CHARACTER*2  sat2lc
      CHARACTER*7  from, to, yyyydoy
      LOGICAL      success
      INTEGER*4    tm, td, ty, doy
      INTEGER*4 msum(13) / 0,  31,  59,  90, 120, 151, 181,
     &                    212, 243, 273, 304, 334, 365 /


      INCLUDE "instdata.cmn"

      sat2lc= 'M3'       !fill in 2-letter instrument designator.

c get initial and final dates

      CALL instdates(sat2lc, from, to)
      yyyydoy= from
      IF (to .EQ. '9999999') THEN
        CALL IDATE(tm, td, ty)
           IF(ty .GT. 70 .AND. ty .LT. 100) ty=ty+1900
           IF(ty .LE. 71) ty= ty + 2000
           doy= msum(tm)+td
           IF( (doy .GE. msum(3)) .AND.
     &         (MOD(ty,   4) .EQ. 0) .AND.
     &         (MOD(ty, 100) .NE. 0) .AND.
     &         (MOD(ty, 400) .EQ. 0) .AND.
     &         (MOD(ty,4000) .NE. 0) )  doy=doy+1

        WRITE(to,'(i4.4,i3.3)') ty, doy
      ENDIF

  100 CONTINUE

        CALL ld_instdata(sat2lc, yyyydoy, 'InstData  ', success)
           IF(.NOT. success) GOTO 110    !just means there's no valid data 
                                         !for this date.

c- - - Do stuff here.


  110   CONTINUE
        IF (yyyydoy .GE. to) GOTO 200
        CALL yyyydoy_inc(yyyydoy)
        GOTO 100


  200 CONTINUE