| Octet No. | Contents |
|---|---|
| 15 | Shape of the Earth (See Code Table 3.2) |
| 16 |
Scale Factor of radius of
spherical Earth |
| 17-20 |
Scale value of radius of
spherical Earth |
| 21 |
Scale factor of major axis of
oblate spheroid Earth |
| 22-25 |
Scaled value of major axis of
oblate spheroid Earth |
| 26 |
Scale factor of minor axis of
oblate spheroid Earth |
| 27-30 |
Scaled value of minor axis of oblate spheroid Earth |
| 31-34 |
Ni—number of points along x-axis |
| 35-38 |
Nj—number of points along y-axis |
| 39-42 |
Basic angle of the initial
production domain (see Note 1) |
| 43-46 |
Subdivisions of basic angle used
to define extreme longitudes and latitudes, and direction increments
(see Note 1) |
| 47-50 |
La1—latitude of first grid point
(see Note 1) |
| 51-54 |
Lo1—longitude of first grid point
(see Note 1) |
| 55 |
Resolution and component flags
(see Table 3.3) |
| 56-59 |
La2—center latitude of grid point
(see Note1) |
| 60-63 |
Lo2—Center longitude of grid point
(see Note 1) |
| 64-67 |
Di—Longitudinal direction increment (see
Note1) |
| 68-71 |
Dj —Latitudinal direction increment (see Note1) |
| 72 |
Scanning mode (flags — see Table 3.4) |
| Notes: 1. Basic angle of the initial production domain and subdivisions of this basic angle are provided to manage cases where the recommended unit of 10-6 degrees is not applicable to describe the extreme longitudes and latitudes, and direction increments. For these last six descriptors, the unit is equal to the ratio of the basic angle and the subdivisions number. For ordinary cases, zero and missing values should be coded, equivalent to respective values of 1 and 106 (10-6 degrees unit). 2. For data on a quasi-regular grid, in which all the rows or columns do not necessarily have the same number of grid points either Ni (octets 31-34) of Nj (octets 35-38) and the corresponding Di (octets 64-67) or Dj (octets 68-71) shall be coded with all bits set to 1 (missing). The actual number of points along each parallel or meridian shall be coded in the octets immediately following the grid definition template (octets [xx+1]-nn), as described in the description of the grid definition section. 3. A quasi-regular grid is only defined for appropriate grid scanning modes. Either rows or columns, but not both simultaneously, may have variable numbers of points. The first point in each row (column) shall be positioned at the meridian (parallel) indicted by octets 47-54. The grid points shall be evenly spaced in latitude (longitude). 4. The rotation of the Latitude/Longitude grid is such that the intersection of the "prime meridian" and the "equator" has been located at the central Latitude and Longitude at the area represented. |