This icon interpolates irregularly spaced point data (in Geopoints format) into a GRIB field, which can then be plotted, saved or combined with other GRIB data. The method used to compute the values of the grid points from the input data depends on the Interpolation Method parameter. The resulting GRIB field can be a regular lat/lon grid of defined size, or else based on a template GRIB file supplied by the user. Note that only the first parameter of a double-valued geopoints vector will be used in the calculations.
The macro language equivalent is geo_to_grib()
The Geopoints To GRIB Editor
Geopoints
Specifies the input data, which must be in Geopoints format (e.g. a geopoints data icon or an Observation Filter icon returning geopoints).
The Bufr Picker Editor
Data
Drop any icon containing or returning BUFR data. This may be, for example, a MARS Retrieval (of observations) icon, a BUFR file icon or an Observation Filter icon (provided it outputs BUFR, not geopoints).
Grib Definition Mode
Output
Specifies the output format you want. Specify one of the geopoints formats (Geographical Points, Geographical Polar Vectors or Geographical X Y Vectors).
Parameter
To specify a parameter enter its unique BUFR descriptor value (a numerical code). Geographical Polar Vectors and Geographical X Y Vectors require two descriptors, separated by a slash (/). The descriptor value is of the form XXYYY, where XX defines the class (e.g. 12 = Temperature class) and YYY the parameter within that class (e.g. 12004 = Dry bulb Temperature at 2m). These descriptor values are different from the ones of the GRIB format. If you do not know the descriptor value, click-left on the assist button to obtain a check list of parameters and associated descriptors. This list only contains the most common parameters. If the one you need is not on the list you can use the BUFR Examiner (right-click, Examine the BUFR file) to see what is there, or up its descriptor value in the "BUFR Reference Manual" (available from http://www.ecmwf.int/products/data/software/bufr.html#description) - see "BUFR Table B", pages 6-19. The significance of code and flag values for non-quantitative parameters are given in the same manual, in "BUFR code table", pages 22-70.
Missing Data
If set to Ignore, missing data is not included in the output file; this is the default behaviour. If set to Include, missing data will be output to the geopoints file, its value being set to that specified by Missing Data Value. Note that when the output format is one of the two geopoints vector formats, the observation is considered missing if one or both of the parameters are missing.