Sodankylä Geophysical Observatory

Ionopspheric soundings

Sodankylä Ionosonde

The Sodankylä Ionosonde started regular, half-hourly vertical soundings of the ionosphere on 1st August 1957. The observatory's second sounder (IS-14) was taken into operation on 1st February 1977. This sounder was modified later on. A new era of ionospheric vertical soundings began on 16th November 2005 when the new "Alpha Wolf" ionosonde was taken into use, which was built from scratch as a research ionosonde by the observatory during the previous three years. The new instrument performed soundings every 10 min until early April 2007, when 1-min soundings for the IPY began.

For technical details of the ionosondes used in SGO, see Instrument Descriptions.

For terminology used see:

URSI Handbook of Ionogram Interpretation and Reduction, second Edition, November 1972 by W.R. Piggott and K. Rawer, WDC A, Report UAG-23. April 1993. (download, e.g., here)

If you are new to this field, you could visit web pages of National Geophysical Data Center (NGDC) to find out what an ionogram is, or to check some terminology related to solar-terrestrial physics.

We have a list of qualifying and descriptive letters available.

Observer in charge:

Dr Alexander Kozlovsky
Sodankylä Geophysical Observatory
Tähteläntie 62
FIN-99600 Sodankylä, Finland
e-mail: to

Last modified: 22 November 2021, 13:50:23.

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