The gribscan utility is used for extracting grid info from GRIB data files. Its features include grid/product information, gridded output in ASCII, binary, and/or grib format, plus automatic "scanning" for GRIB records so that you don't have to know the physical layout of the data to scan it.

The command sytax is:


File Options:

Processing Options:

Display options:


  1. A "quick" scan to get the info GrADS cares about:

    gribscan -q -i eta.T12Z.PGrbF48 | grep 184

    Gives the result:



      184      field # in the file
      F        field data
      135      param #
      108      level indicator
      100      level
      0        l1 byte 1 of level
      100      l2 byte 2 of level
      0        time range indicator
      1e+09    decimal scale factor
      T        time data follows
      1994     year
      8        month
      29       day
      12       hour
      0        min
      1        forecast time unit (hour)
      48       t=48 h forecast
      G        grid param follows
      104      NMC grid #104
      BDTG     Base date-time-group (yymmddhh) follows

  2. Comma delimited output:

    gribscan -d -i eta.T12Z.PGrbF48 | grep 184

    Gives the same results as the previous example but arranged differently:


  3. A full listing:

    gribscan -d -gv -bd -gd -i eta.T12Z.PGrbF48 | grep 184

    Gives the following results:

      PDS,184,104,135,108,100,0,100,1994,8,29,12,0,1,48,0,0,1e+09,mconv,Horizontal moisture divergence,[kg/kg/s],GDS,5,147,110,-139.475,90.755,0.354,-0.268,-105.000,33536.000,0,1,0,BDS,12,-646.844,16170,4825059,26366


    104          grid id
    param #135   mconv,Horizontal moisture divergence,[kg/kg/s]
    BDS          binary data section
    646.844      ref value 16170 - # of points
    4825059      starting byte of the data
    26366        length of the grib message

    Note that eliminating the -d option would result in a fixed-column type output.

  4. Output a selected few fields in GRIB:

    gribscan -og -sp135 -q -i eta.T12Z.PGrbF48 -o eta.135

    Writes out all GRIB message containing the 135 parameter to the file eta.135.grb. A subsequent execution of gribscan on eta.135.grb would return:

    1, F ,135,108,100,0,100,0,1e+09, T,1994,8,29,12,0,1,48,0, G ,104, BDTG, 94082912 2, F,135,108,21860,85,100,0,1e+09, T ,1994,8,29,12,0,1,48,0, G ,104, BDTG, 94082912