GRIB2 - GRID DEFINITION TEMPLATE 3.1100

Hovmoller Diagram Grid with Points
Equally Spaced on the Horizontal

Created 08/09/2005

Preliminary Note:  This template is simply experimental, was not
validated at the time of publication and should be
used only for bilateral previously-agreed tests.


Octet No. Contents
15 Shape of the Earth (See Code Table 3.2)
16
 Scale factor of radius of spherical Earth
17-20 Scaled 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
 Number of horizontal points
35-38
 Basic angle of the initial production domain (see Note 1)
39-42
 Subdivisions of basic angle used to define extreme longitudes and latitudes (see Note 1)
43-46
 La1― latitude of first grid point (see Note 1)
47-50
 Lo1― longitude of first grid point (see Note 1)
51 Scanning mode (flags — see Flag Table 3.4)
52-55
 La2 ― latitude of last grid point (see Note 1)
56-59
 Lo2 ― longitude of last grid point (see Note 1)
60
 Type of horizontal line (see Code table 3.20)
61-64
 NT ― Number of time steps
65
 Unit of offset from reference time (see Code table 4.4i)
66-69 Offset from reference of first time (negative value when first bit set)
70
 Type of time increment (see Code table 4.11)
71
 Unit of time increment (see Code table 4.4)
72-75
 Time increment (negative value when first bit set)
76-82 Last date/time
76-77
 Year
78
 Month
79
 Day
80
 Hour
81
 Minute
82
 Second


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. A scale value of radius of spherical Earth, or major or minor axis of oblate Earth, is derived by applying the appropriate scale factor to the value expressed in metres.


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