Columns Format Description
1-3 A3 Observatory 3-letter code.
4-5 I2 Year (last 2 digits, 82=1982).
6-7 I2 Month (01-12).
8 A1 Element (D, H, X, Y, Z, or F).
9-10 I2 Day of month (01-31).
11-12 A2 Blanks.
13-14 A2 Arbitrary.
15-16 I2 Two blanks or Century digits of the year:
Year 1887 - 18 Century,
Year 1978 - 19 Century,
Year 2014 - 20 Century .
============ Old Format ==============
15 column - International quiet or
disturbed days, Q=1, D=2
16 column - Blank for data since 1900,
8 for data before
17-20 I4 Tabular base, in degrees for D and
in hundreds of nanoTeslas for the intensity elements.
21-116 24I4 Twenty-four 4-digit hourly mean values for the day.
The values are in tenth-minutes for D and in nanoTeslas
for the intensity elements.
The first hourly mean value represents the mean value
between 00:00 UT and 01:00 UT, ..., the 24th value
represents the mean between 23:00 UT and 24:00 UT.
A missing value is identified by 9999.
117-120 I4 Daily mean.
If any of the hourly mean values for the day are missing
9999 will appear as the daily mean.
121-122 Record end marker.
Two chars 'cr'= 13 and 'nl'= 10.
The tabular bases, hourly mean values and daily means are right adjusted
and signed if negative.
Negative values are identified with a minus sign either adjacent to the first
significant digit or in the high-order position of the field.
NOTE: A blank digit will not appear between a (-) sign and the first
significant digit. For example, a value may appear as -050 or b-50
but not as -b50 (b=blank).
The 25 values in positions 21-120 will have the range -999 to 9998,
with 9999 reserved for missing values.
The records are sorted according to observatory code, year, month,
element, day ( positions 1-10).
For the intensity elements we have that
hourly value (nanoTeslas_ = tab.base*100 + tab.value.
For the angles D we have that
hourly value (Degrees) = Tab.base + tab.value/600.
To avoid a 4-digit negative value in positions 21-116,
the tabular base will be adjusted for that day;
for example for D, one degree is subtracted from the base and 600
units are added to each of the hourly values for the day;
for the intensity elements, 500 nT are subtracted from the base and 500 nT
are added to each of the hourly values for the day.