GRIB2 - PRODUCT DEFINITION TEMPLATE 4.72

Post-processing Average, Accumulation, Extreme values
or other Statistically processed values at a horizontal level or in
a horizontal layer in a continuous or non-continuous time interval

Created 07/11/2017


Octet No. Contents
10 Parameter category (see Code Table 4.1)
11 Parameter number (see Code Table 4.2)
12-13 Input process identifier (see Note 1)
14-15 Input originating centre (see Common Code table C–11 and Note 2)
16 Type of post-processing (see Note 3)
17 Type of generating process (see Code Table 4.3)
18
 Background generating process identifier (defined by originating centre)
19
 Forecast generating process identified (see Code ON388 Table A)
20-21 Hours after reference time of data cut-off (see Note 4)
22
 Minutes after reference time data cutoff
23 Indicator of unit of time range (see Code Table 4.4)
24-27
 Forecast time in units defined by octet 23
28 Type of first fixed surface (see Code Table 4.5)
29
 Scale factor of first fixed surface
30-33
 Scaled value of first fixed surface
34 Type of second fixed surfaced (see Code Table 4.5)
35
 Scale factor of second fixed surface
36-39
 Scaled value of second fixed surfaces
40-41 Year ― Time of end of overall time interval
42 Month ― Time of end of overall time interval
43 Day ― Time of end of overall time interval
44 Hour ― Time of end of overall time interval
45 Minute ― Time of end of overall time interval
46 Second ― Time of end of overall time interval
47 n ― number of time range specifications describing the time intervals used to calculate the statistically-processed field
48-51 Total number of data values missing in the statistical process
52-63 Specification of the outermost (or only) time range over which statistical processing is done
52 Statistical process used to calculate the processed field from the field at each time increment during the time range
(see Code Table 4.10)
53 Type of time increment between successive fields used in the statistical processing (see Code Table 4.11)
54 Indicator of unit of time range over which statistical processing is done (see Code Table 4.4)
55-58
 Length of the time range over which statistical processing is done, in units defined by the previous octet
59 Indicator of unit of time for the increment between the successive fields used (see Code Table 4.4)
60-63 Time increment between successive fields, in units defined by the previous octet (see Notes 6 and 7)
64-nn These octets are included only if n>1, where nn = 51 +12 x n
64-75 As octets 52 to 63, next innermost step of processing
76-nn Additional time range specifications, included in accordance with the value of n, Contents as octets 52 to 63, repeated as necessary.


Note: 

(1) The input process identifier shall have the value of the “analysis or forecast process identifier” of the original GRIB message used as input of the post-processing.

(2) The input originating centre shall have the value of the “originating centre” of the original GRIB message used as input of the post-processing.

(3) This identifies which post-processing technique was used. This is defined by the originating centre.

(4) Hours greater than 65534 will be coded as 65534.

(5) The reference time in section 1 and the forecast time together define the beginning of the overall time interval.

(6) An increment of zero means that the statistical processing is the result of a continuous (or near continuous) process, not the processing of a number of discrete samples. Examples of such continuous processes are the temperatures measured by analogue maximum and minimum thermometers or thermographs, and the rainfall measured by a rain gauge.

(7) The reference and forecast times are successively set to their initial values plus or minus the increment, as defined by the type of time increment (one of octets 63, 65, 77, ...). For all but the innermost (last) time range, the next inner range is then processed using these reference and forecast times as the initial reference and forecast times.


Back