# Code table 4.15 - Type of spatial processing used to arrive at given data value from the source data 0 0 Data is calculated directly from the source grid with no interpolation 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 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 # 7-191 Reserved # 192-254 Reserved for local use 255 255 Missing