Understanding Band Conditions Banners

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

Figure 1: HF propagation banner created by Paul L. Herrman, N0NBH

This banner is separated into three sections:

1. The left panel displays date and time (yellow header). Then on separate lines: solar indices (SFI, SN, X-Ray, and 304Å), geomagnetic indices (A, K Plntry), space weather indices (Ptn Flx, Elc Flx), and terrestrial data (Aurora, MUF Boulder ).
2. In the middle, there is a "red" image of the current solar corona that represents radiation strength at 304 Ångstrom
3. The right side of the banner displays the calculated global HF conditions. See how regional conditions vary.

Explanations for the numerical indices displayed on this banner:

SFI: Solar Flux, 2800MHz (10.7cm) ↗ (SFU units) correlates with F2-region ionization; higher value better HF conditions.

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

K-Index ↗: Geomagnetic Disturbance; good conditions K < 3   |   A -Index: 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-region absorption.

304 Å represents the relative strength of total solar radiation in the EUV (extreme ultraviolet) range (that affects F-region ionization), primarily emanating from ionized Helium in the Sun’s photosphere. The designation following the 304Å @ SEM identifies the specific instrument on the SOHO satellite used for the measurement, with these values updated on an hourly basis.

Ptn Flx: Proton Flux Density in the Solar Wind

Elc Flx: Electron Flux Density in the Solar Wind

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

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

The project "Understanding HF Propagation" focuses on near-real-time indicators and explains what they mean.