GRIB2 - GRID TEMPLATE 5.51
Spherical harmonics data - complex packing
Created 10/05/2005

Octet | Contents
--- | ---
12-20 | Same as data representation template 5.50
21-24 | P― Laplacian scaling factor (expressed in 10-6 units)
25-26 | Js ― pentagonal resolution parameter of the unpacked subset (see Note1)
27-28 | Ks ― pentagonal resolution parameter of the unpacked subset (see Note1)
29-30 | Ms ― pentagonal resolution parameter of the unpacked subset (see Note1)
31-34 | Ts ― total number of values in the unpacked subset (see Note1)
35 | Precision of the unpacked subset (see Code Table 5.7)

Notes (1) The unpacked subset is a set of values defined in the same way as the full set of values (on a spectrum limited to Js, Ks and Ms ), but on which scaling and packing are not applied. Associated values are stored in octets 6 onwards of section 7. (2) The remaining coefficients are multiplied by (n x (n+1))p , scaled and packed. The operator associated with this multiplication is derived from the Laplacian operator on the sphere. (3) The retrieval formula for a coefficient of wave number n is then: Y = (R+X x 2e ) x 10-d x (n x(n+1))-p where X is the packed scaled value associated with the coefficient.