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
 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.

J. Ryno, C. Sucksdorff, V. Petrov. Digital geomagnetic data base for VIKING period. IAGA Bull. N 53, 1989.