Stacked daily magnetograms are provided by postscript(PS) files under the
directory "./_ps".  The PS files can be decompressed by "gzip" currently
released as GNU software(gzip-1.2.4.tar is placed in ./misc in this directory).
 Just practice "gzip -d filename.z" ( Three types of files having different
extensions of 'z','g' and 'gz' are found and they are compressed by the same
way. 'g' case is need to use "-S .g" option. "gzip --help" gives short menu.).
Minute sampled files accessible under station name directories (_eureka/ etc.)
were plotted after conversion from H-D-Z to Xm-Ym-Z of the corrected
geomagnetic coordinate components.    The values of rotation angle used
for the conversion are found in "MAGSTNDB".
The plots were made to view quickly geomagnetic activities in the
polar region in response to requests from satellite observation groups
of Geotail or Akebono. So screening of the data is not sufficient and some
data were plotted without correction of time offset. One can easily find
such time offsets, comparing several magnetograms close in the location with
each other.

*  In order to view the compressed Postscript files it is very convenient
for you to refer the files through  WWW client such as Netscape which
automatically make decompression and display PS files on the image viewer
if you define "ghostscript" as a helper.

Please call us for further information about data quality if it is
essential for your research.
hayashi@grl.s.u-tokyo.ac.jp