**MUF
Real-Time ****TROMSO ****Ionosonde Data**

**foF2** =The
ordinary wave critical frequency of the highest stratification in
the F region

**foF1** = The ordinary wave F1 critical frequency

**foE** = The ordinary wave critical frequency
of the lowest thick layer which causes a discontinuity

**fxI** = The top frequency of spread F traces

**foEs** = The highest ordinary wave frequency at
which a mainly continuous Es trace is observed

**fmin** = The lowest frequency at which echo traces
are observed on the ionogram

**MUF(D)** = The
standard transmission curve for 3000 km

**M(D)** = The maximum usable frequency at a defined
distance divided by the critical frequency of that layer

**h'F** = The
minimum virtual height of the ordinary wave trace taken as a
whole

**h'F2** = The minimum virtual height of the
ordinary wave trace for the highest stable stratification in the
F region

**h'E** = The minimum virtual height of the normal E
layer trace

**h'Es** = The minimum height of the trace used to
give foEs

**hmF2** = peak
height, truncated

**hmF1** = peak height

**hmE** = peak height

**yF2** = Parabolic F2 layer semi-thickness

**yF1** = Parabolic F1 layer semi-thickness

**yE** = Parabolic E layer semi-thickness

**B0**** = **Coefficient A0, truncated to integer
km

**B1** = IRI Profile Shape parameter

The Swedish
Ionosondes

Latest Tromsø

SGO MUF Sodankylä
Real-time Data