The Dynasonde at Tromsø

The Dynasonde is a digital HF sounder (see picture) covering ca. 1-30 MHz. It is sometimes refered to as a frequency agile sounder, or Advanced Ionospheric Sounder, hence the acronym FAIS for the software which is used to run it. It can be run like an ionosonde or in other modes such as fixed frequency soundings, even like a partial reflection sounder. Up to 6 Long fat dipoles are used as spaced receiving antennas. They do break sometimes through weight of snow and metal fatigue as they vibrate in the wind. Each half dipole is made from an 11 m long, 15 cm diameter aluminium tube suspended about 2m above the ground. A sample ionogram may be found. The latest and previous soundings are also available. There are other Dynasondes at Halley Bay in the Antarctic, at Bear Lake in Utah, USA, and at Lycksele, Sweden.

The Dynasonde is used in special ways together with the Heating facility at times. This makes it a powerful HF radar as some of our recent API results show.

Another new variant is to use a fixed frequency for so-called IDI (Imaging Doppler Interferometry). Real time IDI results are in postscript as well as other data from previous days.
Some results processed by Owen Jones of BAS for a 24 hour run taken during the Leonids meteor shower on 17 Nov and 18 Nov 1998 are shown here.

There is a CD-ROM list of all soundings recorded since November 1992 when the computer was upgraded to a PC.

A diary of significant events for users is kept here.

Dynasonde workshops are held at irregular intervals.
The first was at Bear Lake in 1997.
A second was held from 13-15 Sept 1999 at the Max-Planck-Institut fur Aeronomie in Linda (am Harz)
A third workshop was held from 21-26 May 2002 in Kiruna and Lycksele, Sweden, the site of a newly installed dynasonde.

Some downloadable stuff, useful only to insiders, is available.

Read a description of ionospheric sounding, as well as a history of the development of the Dynasonde including a more detailed explanation of its design. There is a list of Tromso dynasonde publications and a list of references from 1979 to 1994 relating to Dynasondes.

How to use the Dynasonde

Tips on starting and running the sounder exist, as well as instructions to save the resulting DOS data files to Exabyte or DAT tapes are now obsolete. The archiving is now done to CD-ROMs.

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Related Sites:

Bear lake Observatory Dynasonde in Utah
and a Quicktime movie of soundings from Bear Lake.
The Swedish Ionosonde Network
The Tromso Digisonde
The Ionograms from Warsaw