GRIB2 - GRID DEFINITION TEMPLATE 3.20

Polar stereographic projection

Created 07/20/2005


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
Nx ― number of points along the x-axis
35-38
Ny ― number of points along the y-axis
39-42
La1 ― latitude of first grid point
43-46
Lo1 ― longitude of first grid point
47 Resolution and component flags (see Flag Table 3.3 and Note 1)
48-51
LaD ― latitude where Dx and Dy are specified
52-55
LoV ― orientation of the grid (see Note2)
56-59
Dx ― x-direction grid length (see Note 2)
60-63
Dy ― y-direction  grid length (see Note 3)
64
Projection centre flag (see Flag Table 3.5)
65
Scanning mode (see Flag Table 3.4)


Notes:

1.  The resolution flags (bits 3-4 Flag table 3.3) are not applicable

2.  LoV is the longitude value of the meridian which is parallel to the
y-axis (or columns of the grid) along which latitude increases as the y-coordinate
increases (the orientation longitude may or may not appear on a particular grid).

3.  Grid length is in units of 10-3  m at the latitude specified by LaD. 
4.  Bit 2 of the projection flag is not applicable to the polar stereographic projection.

5.  A scale 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.


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