BYTE   MNEM  CONTEXT

  1 - 2   NR    Record length  in bytes  (usually 416)
  3 - 6   STCOD IAGA station code, 3 letters, 4th arbitrary
  7 - 9   CMP   order of the components in data block, 3
  10            letters and space
  11      SC    scaling factor, multiply all data and base
                values by X (SC=0 X=1, SC=1..7 X=2**(3-X),
                S=8..11 X=10**(10-X)) to yield data in nT or
                0.1' unit
  12      SD    source of data, 0-digital record, 1-digitized
                from analog magnetograms
  13      BL    base level information, 0-absolute values;
                1-final variometer data ,no absolute measur
                ement; 2-variations from monthly quiet mean
                level; 3- variations from monthly quiet night
                mean level; 10, 11, 12, 13- the same, but
                preliminary data
 14-18          free (0)
 19-20    FB    filter breakpoint, period in seconds in which
                low pass filter is 3 db  down (0.7 ampl.);
                0- average for sample interval; 9999-no
                filtering; $7FFF-unknown
 21-22    SI    sample interval in second (60 for 1-min)
 23-24    DS    number of time samples in record (60)
 25-26    GNPD  geographical north pole distance in 0.01
                degrees
 27-28    GLON  geographical longitude in 0.01 degrees
                (eastward positive)
 29-30    YY    year (1900-1999)
 31-32    MM    month (1-12)
 33-34    DD    day (1-31)
 35-36    HH    hour (0-23)
 37-38    MN    minute (0-59) of record start (0 for 1-min)
 39-40    MV1   mean value for the 1-th component (usually
                X or H)
 41-42    MV2   mean value for the 2-nd component (usually
                Y or E)
 43-44    MV3   mean value for the 3-rd component (usually Z)
 45-48    BS1   base level for the 1-th comp, 4 bytes integer
 49-52    BS2   base level for the 2-nd comp, 4 bytes integer
 53-56    BS3   base level for the 3-rd comp, 4 bytes integer
 57-176   V1    60 values for the 1-th component
177-296   V2    60 values for the 2-nd component
297-416   V3    60 values for the 3-rd component


Field 3-10 are ASCII characters,
others are binary bytes or 2 bytes integers.
Components code: D,I-in 0.1'; H,F,X,Y,Z in nT;
E-magnetic east component perpendicular to H in nT;
Usually data recorded as XYZ.
Missing values are marked by 7FFF hecadec (32767).
Mean values are calculated if no more then 10 values
are missing.