0 0 Data is calculated directly from the source grid with no interpolation (see note 1)
1 1 Bilinear interpolation using the 4 source grid grid-point values surrounding the nominal grid-point
2 2 Bicubic interpolation using the 4 source grid grid-point values surrounding the nominal grid-point
3 3 Using the value from the source grid grid-point which is nearest to the nominal grid-point
4 4 Budget interpolation using the 4 source grid grid-point values surrounding the nominal grid-point (see note 2)
5 5 Spectral interpolation using the 4 source grid grid-point values surrounding the nominal grid-point
6 6 Neighbor-budget interpolation using the 4 source grid grid-point values surrounding the nominal grid-point (see note 3)
#7-191 Reserved
#192-254 Reserved for Local Use
255 255	Missing