What are the INTERMAGNET data types ?
INTERMAGNET has used two data formats for the dissemination of non-definitive data: INTERMAGNET Minute Mean Format (IMF) and IAGA-2002 format. The IMF format is being phased out (from 2013 data in IMF format will no longer be distributed from the INTERMAGNET web site). The data types in the two formats are:
INTERMAGNET Data Types
|IMF||Reported||Data are defined as: the raw data obtained from the INTERMAGNET Magnetic Observatory (IMO), either by satellite, computer link, or other means. It will be formatted in either version IMFV2.8N (binary) or IMFV1.2N (ASCII) without any Baseline Reference Measurements (BRM), or other modifications applied to it.|
|IMF||Adjusted||Data are defined as: the Reported data with Baseline Reference Measurements (BRM), spike removal, timeshifts, and/or other modifications applied to it. It is emphasized that only one (1) adjusted version of the data would be allowed, to be completed within 7 days of receipt of the Reported data to prevent the proliferation of multiple versions of the Adjusted data.|
|IMF||Quasi-definitive||Data are defined as data that have been corrected using provisional baselines. Produced soon after their acquisition, their accuracy is intended to be very close to that of an observatory’s definitive data product. 98% of the differences between quasi-definitive and definitive data (X, Y, Z) monthly mean values should be less than 5nT.|
|IMF||Definitive||Data are defined as the final adopted data values. Definitive data will only be distributed by the institution responsible for the observatory.|
|IAGA||Variation||The IAGA-2002 format does not describe the data types.|
|IAGA||Provisional||The IAGA-2002 format does not describe the data types.|
|IAGA||Quasi-definitive||The IAGA-2002 format does not describe the data types.|
|IAGA||Definitive||The IAGA-2002 format does not describe the data types.|
The two data types quasi-definitive and definitive are well defined and have the same meaning when used in either of the two data types. The remaining data types are less clearly defined. Some computer software uses the IMF reported data type interchangeably with the variation data type, also the IMF adjusted data type with the IAGA-2002 provisional data type, and this is the policy used in INTERMAGNET.
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