Geomagnetic Observation by Magnetometer Network.
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Some notes
* On July 5, 2010, the one-min ascii files of 1990-2010 was re-made from
one-second files, in order to correct the element symbol E (X,Y,Z-->H,D,Z)
in the one-min ascii files, and to consistently calculate the
1-min averages. We found that the data copied before July 5, 2010 may
contain mixture of one-min average and one-min sampled data from the
original one-second sampled data.
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Time Tag Errors
interval stn error
Oct.30-Nov.19, 1991 LEM Time tag data are 2 hours behind the correct time.
Nov.2-16, 1991 BRV Time tag data are 1 hour ahead of the correct time.
Nov.24-Dec.7, 1992 BRV Time tag data are 10 hours ahead of the correct time.
Nov.25-Dec.6, 1993 ADL Time tag data are 1 hour behind the correct time.
Dec.7,'93-Jan.17,'94 KOT Time tag data are 2 hours behind the correct time.
Jan.18-22, 1994 CBI Time tag data are 9 hours ahead of the correct time.
Mar.18-Apr.27, 1994 CBI Time tag data are 1 day behind the correct time.
Mar.17-Apr.18, 1994 WEP Time tag data are 6 hours behind the correct time.
Apr.21-Jul.29, 1994 WEP Time tag data are 6 hours behind the correct time.
Mar.24-May 6, 1995 BRV Time tag data are 1 day behind the correct time.
Apr.7-9, 1995 ADL Time tag data are 1 hour behind the correct time.
Apr.27-29, 1995 ADL Time tag data are 1 hour behind the correct time.
May 23-25, 1995 ADL Time tag data are 1 hour behind the correct time.
Nov.1-Dec.9, 1995 CBI Time tag data are 12 hours behind the correct time.
Mar.9-28, 1996 ADL Time tag data are 1 day ahead the correct time.
Feb.15-Mar.7, 1997 ONW Time tag data are 1 day behind the correct time.
Feb.28, 1997 BIK Time tag data are 1 hour behind the correct time.
Mar.5-12, 1997 YAP Time tag data are incorrect.
May 22-29, 1997 YAP Time tag data are incorrect.
Jul. 1-Dec. 31, 1997 YMK Time tag data are 9 hours ahead the correct time.
Apr.29-May 22, 1998 WEP Time tag data are 12 hours ahead the correct time.
Apr.24-May 22, 1998 DAL Time tag data are 1 hour behind the correct time.
Aug.29-Sep.17, 1998 DAL Time tag data are 1.5 hour behind the correct time.
Sep.24-Oct.22, 1998 DAL Time tag data are 1.5 hour ahead the correct time.
Nov.16, 1998 -
Jun 19, 1999 DAL Time tag data are 1.5 hour ahead the correct time.
Apr.14-May 7, 1999 KAT Time tag data are 9 hours ahead the correct time.
Apr.4-19, 2001 MCQ Time tag data are 12 hours ahead of correct time.
Apr.20-Sep.22, 2001 MCQ Time tag data are 1 day ahead the correct time.
Apr.12-Jun.15, 2002 MCQ Time tag data are 2 days behind the correct time.
Jun.16-Jul.4, 2002 MCQ Time tag data are 1 day behind the correct time.
Oct.4-26, 2002 ONW Time tag data are 3 hours ahead the correct time.
Aug.8-Oct.27, 2003 BIK H and Z are exchanged, time tag may be incorrect in max 13 sec due to GPS receiver error.
Feb.4-July 10, 2005 KTB Time tag data may be delayed for maximum 52 sec from the correct time (network NTP stop in this interval).
Sep.8, 2007-Jan.28, 2009 KAG H and D components are short-circuited in the cable before the data recorder.
Sept.7, 2009-June 2 0110UT, 2010: RIK Time tag data was shifted a few min to 2-3 hours due to the lack of clock correction.
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some more notes for the data
BSV(BRV):
some data jump in the first half of 2008
Z-component was stopped on Aug-Sept.2008
sometimes GPS clock fails and the time may have offset of ~14 sec
CHD:
large noise on March, August-Sept, 2008
KTN:
large drift in H and D components for Jun-Oct 2007.
LMT:
080223-080304: output satulation
091110-091112: H-component satulation
091110-091119: D-component satulation
091112-091114: Z-component satulation
MGD:
output drift on Nov.2007 and after May, 2008
abnormal output after July 2007 in D-component
output satulation in August 2008
PPI:
output drift for Feb-Mar, 2007, Jan-Apr, 2008, and Dec 2008-Feb 2009
TIK:
large noise up to Sept 2008
ZYK:
large noise
no GPS correction before Sept.2007
MSR:
Sinusoidal noise with a period of tens of seconds sometimes
appears in all three components after January 2010.
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Channel Correspondence:
a) The each channel corresponds to each value as follows.
ch.1:H ch.2:D ch.3:Z ch.4:time pulse
ch.5:dH/dt ch.6:dD/dt ch.7:dZ/dt ch.8:meaningless
(for the (new) data from CBI)
ch.1:H ch.2:Z ch.3:D ch.4:time pulse
ch.5:dH/dt ch.6:dZ/dt ch.7:dD/dt ch.8:meaningless
b) Directions of magnetic sensors are as follows.
(1) for the data from the stations in the northern hemisphere,
for data from WEP before 05UT on Jan. 31, 1991
and for data from ADL before July 14, 1993
[H:+ = northward] [D:+ = eastward] [Z:+ = downward]
(2) for the data from the stations in the southern hemisphere,
[H:+ = northward] [D:+ = eastward] [Z:+ = upward]
(3) for data from CBI
[H:+ = northward] [D:+ = westward] [Z:+ = downward]
(4) for data from WEW
[H:+ = northward] [D:+ = westward] [Z:+ = upward]
c) Some other remarks
* The Z-component of BSV data sometimes becomes zero due to a
temporal disconnection of cable.
* The Z-component of ADL data sometimes shows noisy fluctuations
due to an equipment problem.
* The Z-component of DAL data is meaningless after Jan. 1, 1993.
* The D- and Z-components of MSR data have a DC-level, artificial
fluctuation on a few days/year.
* ADL is the Adelaide station (ADE).
* The H-component of EWA data sometimes shows noisy fluctuations
due to an equipment problem
* The D-component of DAL data satulate for April 13, 1992 - July
10, 1992
Geomagnetic Observation by Magnetometer Network.