Understanding HF propagation banners

This page is part of the project "Understanding HF Propagation"
by Doron Tal, 4X4XM

Banners provide online information on radio propagation conditions for specific ham bands, including current status and numerical values, based on real-time data from various sources.

Please see the following banner (courtesy of Paul L Herrman, N0NBH) as an example:

Explanations for the numerical indices displayed on this banner:

SFI - Solar Flux, 2800MHz (10.7cm)

(SFU units) correlates with F2-layer ionization; higher value better HF conditions.

SN - Daily Sunspot Number is a measure of the solar activity; like SFI it correlates with enhanced F2-layer i.e. better HF conditions

K-Index

: Geomagnetic Disturbance; good conditions K < 3 | A -Index ref.

: 24 hours Average; good conditions A < 10

X-Ray; Scales: A, B, C, M, and X (range from A_0.0 to X_9.9) affect D-layer absorption

304 Å: Total Solar Radiation SEM (Solar EUV Monitor) wavelenth: 304 Ångstroms (30.4nm) that affects F-layer ionization

Ptn - Proton Flux Density | Elc - Electron Flux Density in the Solar Wind; both impact E-region

Aurora indicates the strength of the ionization of the E-region in the polar regions

MUF Boulder - Maximum Usable Frequency (MHz) at Boulder, CO, USA, updated every 15 minutes.

GeoMag - Calculated - Earth`s Geomagnetic based on K-Index. Updated every 3 hours.

Sig Noise - Calculated every ½ hour: S-units (Solar Wind and Geomagnetic Activity)

The project "Understanding HF Propagation" provides a detailed overview and tutorials on HF propagation.