KSEC1 element	Contents	GRIB octet	Recommended GRIB_API keys	Coded GRIB_API keys	Comments
37	ECMWF local GRIB use definition identifier. 14 = Brightness temperature.	41	localDefinitionNumber	localDefinitionNumber
38	Class	42	class	marsClass
39	Type	43	type	marsType
40	Stream	44-45	stream	marsStream
41	Version number or experiment identifier. (4 ASCII characters, right justified)	46-49	expver	experimentVersionNumber
42	As for MARS labelling (eg set to zero, or ensemble forecast number if appropriate)	50	number	perturbationNumber
43	As for MARS labelling (eg set to zero, or total number in ensembles if appropriate)	51	numberOfForecastsInEnsemble	numberOfForecastsInEnsemble
44	Channel number	52	channel	channelNumber
45	Integer scaling factor applied to frequencies in following list of frequency definitions (4-byte integer)	53-56	scalingFactorForFrequencies	scalingFactorForFrequencies
46	Total number of frequencies (Nf)	57	numberOfFrequencies	numberOfFrequencies
-	Spare (set to zero)	58-60
47->(46+Nf)	List of Nf scaled frequencies (4-byte integers)	61->(60+Nf*4)	listOfScaledFrequencies	listOfScaledFrequencies	numberOfFrequencies values.
-	Spare (set to zero)	(61+Nf*4)->1080