Grid definition - Gaussian latitude/longitude grid (including rotated, stretched, or stretched and rotated)

      Octet
      No.
      Contents
      7-8Ni - number of points along a parallel
      9-10Nj - number of points along a meridian
      11-13La1 - latitude of first grid point
      14-16Lo1 - longitude of first grid point
      17Resolution and component flags (see Code table 7)
      18-20La2 - latitude of last grid point
      21-23Lo2 - longitude of last grid point
      24-25Di - i direction increment
      26-27N - number of parallels between a pole and the equator
      28Scanning mode (flags - see Code table 8)
      29-32Set to zero (reserved)
      33-35Latitude of the southern pole in millidegrees (integer)
      Latitude of pole of stretching in millidegrees (integer)
      36-38Longitude of the southern pole in millidegrees (integer)
      Longitude of pole of stretching in millidegrees (integer)
      39-42Angle of rotation (represented in the same way as the reference value)
      Stretching factor (representation as for the reference value)
      43-45Latitude of pole of stretching in millidegrees (integer)
      46-48Longitude of pole of stretching in millidegrees (integer)
      49-52Stretching factor (representation as for the reference value)



      NOTES:

      1. Latitude, longitude and increments are in millidegrees.

      2. Latitude values are limited to the range 0-90000; bit 1 is set to 1 to indicate south latitude.

      3. Longitude values are limited to the range 0-360000; bit 1 is set to 1 to indicate west longitude.

      4. The number of parallels between a pole and the equator is used to establish the variable (Gaussian) spacing of the parallels; this value must always be given.

      5. The latitude and longitude of the last grid point and the first grid point should always be given for regular grids.

      6. Where items are not give, the appropriate octet(s) should have all bits set to 1.

      7. See Notes 6 to 11 under Grid definition - latitude/longitude grid (or equidistant cylindrical).

      8. Quasi-regular Gaussian latitude/longitude grids are defined only for subsets of global grids containing full latitude rows (360°).

      9. For data on a quasi-regular grid, in which all rows do not necessarily have the same number of grid points, Ni (octets 7-8) and the corresponding Di (octets 24-25) shall be coded with all bits set to 1 (missing); the actual number of points along each parallel shall be coded.

      10. A quasi-regular Gaussian latitude/longitude grid is only defined for the grid scanning mode with consecutive points on parallels (bit 3 set to zero in Code table 8). The first point in each row shall be positioned at the meridian indicated by octets 14-16 and the last shall be positioned at the meridian indicated by octets 21-23. The grid points along each parallel shall be evenly spaced in longitude.



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