Solar conditions

Solar-Terrestrial data

The Solar Widget is based on data from the United States National Oceanic and Atmospheric Administration (NOAA). The raw data is publicly available -in text format- here.

To make any sense of the raw data takes some computational power. After a some trial-and-error and experimenting I came up with an algorithm that I feel represents the HF propagation conditions quite well. So now is the time to go public with my widget.

Please feel free to test and try and contact me with remarks, suggestions, errors or whatever else is relevant.

Solar widget

The RigReference Solar Widget gives an indication of the conditions on the various ham bands, for both day and night time.

How to use...

...on WordPress blogs?

If you're using WordPress, you're in luck. We've developed a WordPress solar-plugin which is easy to install and requires zero technical knowlegde. The plugin also allows you to switch between widget layouts from the WordPress admin pages.

...on all other sites?

For all other sites, incorporating the solar widget in your own site requires you copy-paste the code below into your own page -at the location where you want the widget to be displayed.

Conditions widget in wide format	Javascript: <div id="rigref-solar-widget"></div><script type="text/javascript">(function() {var a = document.createElement('a');var i = document.createElement('img');var s = document.getElementById('rigref-solar-widget');a.href = ('https://rigreference.com/solar');a.target = '_blank';i.src = ('https://rigreference.com/solar/img/wide');i.border = 0;a.appendChild(i);s.appendChild(a);})();</script>	Plain html: <div id="rigref-solar-widget"><a href="https://rigreference.com/solar" target="_blank"><img src="https://rigreference.com/solar/img/wide" border="0"></a></div>
Conditions widget in tall format	Javascript: <div id="rigref-solar-widget"></div><script type="text/javascript">(function() {var a = document.createElement('a');var i = document.createElement('img');var s = document.getElementById('rigref-solar-widget');a.href = ('https://rigreference.com/solar');a.target = '_blank';i.src = ('https://rigreference.com/solar/img/tall');i.border = 0;a.appendChild(i);s.appendChild(a);})();</script>	Plain html: <div id="rigref-solar-widget"><a href="https://rigreference.com/solar" target="_blank"><img src="https://rigreference.com/solar/img/tall" border="0"></a></div>
Conditions widget for the Navtex band, 600 meter / 518 kHz Custom made for www.navtex.net	Javascript: <div id="rigref-solar-widget"></div><script type="text/javascript">(function() {var a = document.createElement('a');var i = document.createElement('img');var s = document.getElementById('rigref-solar-widget');a.href = ('https://rigreference.com/solar');a.target = '_blank';i.src = ('https://rigreference.com/solar/img/navtex');i.border = 0;a.appendChild(i);s.appendChild(a);})();</script>	Plain html: <div id="rigref-solar-widget"><a href="https://rigreference.com/solar" target="_blank"><img src="https://rigreference.com/solar/img/navtex" border="0"></a></div>
Conditions widget for the CB / 11 meter band	Javascript: <div id="rigref-solar-widget"></div><script type="text/javascript">(function() {var a = document.createElement('a');var i = document.createElement('img');var s = document.getElementById('rigref-solar-widget');a.href = ('https://rigreference.com/solar');a.target = '_blank';i.src = ('https://rigreference.com/solar/img/cb');i.border = 0;a.appendChild(i);s.appendChild(a);})();</script>	Plain html: <div id="rigref-solar-widget"><a href="https://rigreference.com/solar" target="_blank"><img src="https://rigreference.com/solar/img/cb" border="0"></a></div>

HF-band conditions (day/night)

These are the values I calculated from the raw NOAA data. There isn't any golden rule for calculation propagation conditions. I've put together an algorithm based on data from different sources. /p>

Band	Day	Night
600 meter	Good (99)	Good (175)
160 meter	Fair (61)	Good (98)
80 meter	Fair (52)	Good (81)
40 meter	Poor (46)	Fair (70)
20 meter	Poor (42)	Fair (61)
10 meter	Poor (39)	Fair (55)
6 meter	Poor (38)	Fair (52)

Paul Herrman (N0NBH) has a fantastic site if you're into solar and weather data. I've used his info a lot.

Latest measurement - raw data

This is the latest measurement from NOAA. I use these values to estimate current propagation conditions.

Parameter	Value	Remarks
Time	2024-12-02 15:05:00 UTC	Time of measurement
Ai	7	A-index
Ki	1	Planetary K-index
SFi	186	Solar Flux index
Proton flux	1.5900045633316
Electron flux	58.548736572266
X-Ray	C1.8
Calculated conditions
Signal/Noise level	S0-1	Background S/N level
Geomagnetic field	Very quiet	Ranges from Very quiet to Storm
MUF	35 MHz	Maximum Usable Frequency

Historic data

Solar activity as recorded by NOAA of the past 7 days. Solar flares can be seen especially in the K-index graph as large spikes. Shortwave propagation can be severely affected by flares, causing higher noise levels and weaker signals.

A_i indicates a daily average level for geomagnetic activity. Values range from about 0 to 400. A_i is the average of eight 3-hour K_i values and provides a level of instability in the earth's geomagnetic field. Instability is greatest when both A_i and K_i are high. This can cause HF-signals to fade and paths to open and close with little warning. A high K_i and low A_i indicates an abrupt disturbance in the geomagnetic field, resulting in intense but brief disruptions in HF-propagation. A_i is recorded once a day.

K_i indicates the disturbance in the horizontal component of the earth's magnetic field. Values range from 0 to 9 and are based on 3-hour interval measurements in nT (nano Tesla). The higher the K_i-value, the more static and interference you can expect. K_i-values have more impact at higher latitudes (closer to the poles).

SF_i (Solar Flux Index) is the solar radiation measured at 2800 MHz (10.7cm) and gives a good indication of the F-layer ionization. The higher the number, the more the ionization, which gives us nice DX openings on HF-bands. Higher bands are less affected by SF_i. Measurements range from about 60 to 300 and are recorded 3 times per day. The up and down motion is caused by the rotation of the sun which has a cycle of 28 days.