Section 3 - Template 40 : Gaussian latitude/longitude
Templates for Section 3
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| Octets | Key | Type | Content |
| 15 | shapeOfTheEarth | codetable | Shape of the earth (see Code Table 3.2) |
| 16 | scaleFactorOfRadiusOfSphericalEarth | unsigned | Scale factor of radius of spherical earth |
| 17-20 | scaledValueOfRadiusOfSphericalEarth | unsigned | Scaled value of radius of spherical earth |
| 21 | scaleFactorOfMajorAxisOfOblateSpheroidEarth | unsigned | Scale factor of major axis of oblate spheroid earth |
| 22-25 | scaledValueOfMajorAxisOfOblateSpheroidEarth | unsigned | Scaled value of major axis of oblate spheroid earth |
| 26 | scaleFactorOfMinorAxisOfOblateSpheroidEarth | unsigned | Scale factor of minor axis of oblate spheroid earth |
| 27-30 | scaledValueOfMinorAxisOfOblateSpheroidEarth | unsigned | Scaled value of minor axis of oblate spheroid earth |
| 31-34 | Ni | unsigned | Ni - number of points along a parallel |
| 35-38 | Nj | unsigned | Nj - number of points along a meridian |
| 39-42 | basicAngleOfTheInitialProductionDomain | unsigned | Basic angle of the initial production domain (see Note 1) |
| 43-46 | subdivisionsOfBasicAngle | unsigned | Subdivisions of basic angle used to define extreme longitudes and latitudes, and direction increments (see Note 1) |
| 47-50 | latitudeOfFirstGridPoint | signed | La1 - latitude of first grid point (see Note 1) |
| 51-54 | longitudeOfFirstGridPoint | signed | Lo1 - longitude of first grid point (see Note 1) |
| 55 | resolutionAndComponentFlags | codeflag | Resolution and component flags (see Flag Table 3.3) |
| 56-59 | latitudeOfLastGridPoint | signed | La2 - latitude of last grid point (see Note 1) |
| 60-63 | longitudeOfLastGridPoint | signed | Lo2 - longitude of last grid point (see Note 1) |
| 64-67 | iDirectionIncrement | unsigned | Di - i direction increment (see Notes 1 and 5) |
| 68-71 | N | unsigned | N - number of parallels between a pole and the equator (see Note 2) |
| 72 | scanningMode | codeflag | Scanning mode (flags - see Flag Table 3.4) |
| 73-nn | pl | unsigned | List of number of points along each meridian or parallel (These octets are only present for quasi-regular grids as described in note 4) |
( 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, 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) 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.
( 3) A scaled value of radius of spherical Earth, or major or minor axis of oblate spheroid Earth is derived from applying appropriate scale factor to the value expressed in metres.
( 4) 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) indicated by Octets 47-54. The grid points shall be evenly spaced in latitude (longitude).
( 5) It is recommended to use unsigned direction increments