IYFV1.01 INTERMAGNET CD-ROM/DVD Format For Yearmean File

Note : The following content describes the format of a file. If you are using a screen reader, you may have difficulty reading this content. For any assistance, please contact the webmaster.

Magnetic data with 1nT or 0.1min of arc resolution are organized on a year file basis. One file contains all published annual mean values of the geomagnetic field components at a single observatory.

File name: YEARMEAN and the three-letter observatory ID code as an extension. eg: YEARMEAN.BOU for Boulder.

Each file may have from 1 to 3 tables containing annual mean values. The file must contain a table of annual means for ALL-DAYS, but may also contain tables of annual means for QUIET-DAYS and DISTURBED-DAYS.

Description of the bloc header

The header contains information on observatory name, ID-code, Colatitude, Longitude and Elevation. It further contains the headers for each data columns. See Sample of IYFV1.01 CD-ROM/DVD yearmean file for an example.

Description of data space (75 characters per line including CrLf)

All data fields are right-justified. The field width must be maintained, either by zero-filling or space-filling. The '+'sign for positive values is optional.


Description of data space
Parameter Description
YYYY.yyy Epoch is given with 3 decimals.
DDD_dd.d Declination is given in degrees and decimal minutes of arc.
III_ii.i Inclination is given in degrees and decimal minutes of arc.
HHHHHH H-component is given in nT.
XXXXXX X-component is given in nT.
YYYYYY Y-component is given in nT.
ZZZZZZ Z-component is given in nT.
FFFFFF F-component is given in nT.
A Type of annual means. May be All, Quiet, Disturbed, Incomplete or Jump. The J is not an annual mean value, but indicates a jump in the observatory recordings, which should be described in a note.
EEEE recorded elements. eg:"XYZF" or "HDZF".
NNN Note number
CRLF Indicates a Carriage return, Line feed.

Missing elements in an annual mean record should be represented with 9s. Missing angular values should be coded as three 9 digits, a space, two 9 digits a dot and one 9 digit: 999 99.9

Missing field strengths should be coded as six 9 digits: 999999

Description of the footer

At the end of the file is added a footer describing the data. The footer contains notes on jumps , incomplete data sets etc. See Sample of IYFV1.01 CD-ROM/DVD yearmean file for an example.