Realtime Tromso: and SvalbardLatest sounding (DSND analysis) and database
The links below are from the older DSND which will be phased out.
Critical frequencies in a 48-hr plot.
Vector velocities in a 48-hr plot
Some older critical frequency tables.
Plot archives from an older version of DSND analysis:Previous 24-hr critical frequency plots.
Previous 24-hr vector velocity plots.
The NOAA site where other worldwide sounders are available.
Realtime Tromso: and SvalbardLatest (self-updating) ionogram.
New and old colour plot of plasma frequency in a self-updating 24-hr plot.
'Raw' ionogram archives:Previous 24-hr plasma frequency plots
Previous 24-hr angle of arrival (n-s) plots
Daily zipped archives of individual 'raw analysis':
ionograms (with polarization in colour)
and skymaps (with Doppler in colour).