Radio propagation 101
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The document discusses the dual impact of the sun on amateur radio, highlighting the significance of sunspot activity and its relation to radio propagation. It explains how varying sunspot numbers affect ionization in the ionosphere, influencing communication during the day and night. Additionally, it covers terminology associated with radio wave propagation, emphasizing the complexities of predicting sunspot cycles and their effects on signal transmission.
Radio propagation 101
- 1. Our Sun: Good guy or bad guy? Radio PropagationRadio Propagation 101101
- 2. As it turns out, the sun is a mixture of both for Amateur radio. Lets talk about the sun first!
- 3. NASA Solar imagesNASA Solar images on Jan 23 – 2012on Jan 23 – 2012 Cycle 24 due to peakCycle 24 due to peak early 2013. There isearly 2013. There is plenty of dailyplenty of daily sunspot activity atsunspot activity at presentpresent
- 4. SunspotsSunspots Sunspots are temporary dark spots that appear on the surface of the Sun. Sunspot temperatures are at 3000–4500 K (2727–4227 °C),while the surrounding sun activity is at about 5,780 K. Being colder sunspots appear darker. Isolated, they would be brighter than an electric arc. Sunspots expand and contract as they move across the surface of the Sun and can be as large as 80,000 Km (50,000 mi) in diameter, making the larger ones visible from Earth without the aid of a telescope.
- 5. SSN &SSN & SFISFI – They are not the same– They are not the same Sun Spot Number Increased sunspot numbers indicate increasing iononizing radiation of our ionosphere. They vary from zero to over 200 during the peak of the 11 year cycle. Solar Flux Index This is a measurement taken of radio signals taken from the sun at 2800 Mhz (10.7 Cm) Solar Flux values range from 60 (No sunspots) to 300
- 7. What the Solar Flare Numbers mean
- 8. Magnetic & X-Ray Sun RadiationMagnetic & X-Ray Sun Radiation
- 9. Geomagnetic Storms can be your Friend!
- 10. What is the “A” Index and “K” Index?What is the “A” Index and “K” Index? ““A” IndexA” Index ““K” Index?K” Index? The A Index describes the Geomagnetic conditions for the past 24 hours. The K Index describes the Geomagnetic conditions for the past 3 hours.
- 11. How do weHow do we know what theknow what the sunspotsunspot activity isactivity is doing daily?doing daily? TheseThese updatedupdated charts are oncharts are on must amateurmust amateur radio websitesradio websites Realtime Sunspot ChartsRealtime Sunspot Charts
- 12. The Indexes can change rapidlyThe Indexes can change rapidly
- 13. Geomagnetic Storm Warning Its coming at you!!!
- 14. Where are we heading?Where are we heading? Sunspots were rarely observed during the Maunder Minimum in the second part of the 17th century (approximately from 1645 to 1715). This coincides with part of a period of cooling known as the Little Ice Age. Sunspots quickly rise and more slowly fall on an irregular cycle of 11 years, For example, from 1900 to the 1960s the solar maximum trend has been upward. From the 1960s to the present is slowly edging downwards.
- 15. Sunspot Cycles – Every 11 Years Sunspot Cycles are Notoriously Difficult to Accurately Predict. Solar physicists believe that the speed of a massive circulating current of hot plasma within the Sun predicts the amplitudes of sunspot cycles approximately twenty years into the future. In the years prior to 2006 that speed had become lower than ever before observed. The National Center for Atmospheric Research predicted Cycle 24 would be intense. NASA predicted Cycle 25 will be extraordinarily weak. The NCAR prediction for Cycle 24 is shown above in pink. NASA's Cycle 24 and 25 predictions are shown in red. Bugger! The Boffins got it wrong!!!!
- 16. Cycle 24Cycle 24
- 17. Pathetic Cycle 24 on it’s way to 2020Pathetic Cycle 24 on it’s way to 2020
- 18. How Does the Sun Affect our Ionosphere?How Does the Sun Affect our Ionosphere?
- 19. Ionospheric D LayerIonospheric D Layer
- 20. Ionospheric E LayerIonospheric E Layer
- 21. Ionospheric F LayersIonospheric F Layers
- 23. Ionized Ionospheric LayersIonized Ionospheric Layers
- 24. It is all VERY confusing!It is all VERY confusing! How does Radio Propagation work forHow does Radio Propagation work for us during the day and during the night?us during the day and during the night? Answer: Very well indeed!Answer: Very well indeed! It all depends on the Sunspot activityIt all depends on the Sunspot activity and the time of day or nightand the time of day or night This is how it works ….........This is how it works ….........
- 25. Know How the Layers Work and You will Work DX
- 26. Angle of Radiation -Verticals Rule?Angle of Radiation -Verticals Rule?
- 27. Angle of radiation is not just a theory…Angle of radiation is not just a theory… It’s real – if you want to work DXIt’s real – if you want to work DX High angle of radiation – Little or no reflection andHigh angle of radiation – Little or no reflection and no DXno DX Low angle of radiation – Good reflection and you workLow angle of radiation – Good reflection and you work DX!DX!
- 28. Propagation Terms 1Propagation Terms 1 Ground Wave Are signals that travel on the surface of the earth for short distances Skywave Are signals that reflect off the Ionosphere layers. It is the primary mode of long distance communication. Absorption The D and E layers absorb signals below 4 Mhz during the day Critical Frequency The highest frequency at which reflections are returned to earth from a vertical incidence
- 29. Propagation Terms 2Propagation Terms 2 Sporadic E Skip When the E layer becomes highly charged permitting reflection of signals up to 200 Mhz for a few minutes to a few hours Tropospheric Ducting Where waves get trapped between layers and goes long distances. Usually happens over water. Wonderful news for 6M addicts! Wave Angle The angle at which radio waves leave the earth and reflect off the Ionosphere and back to earth. The angle determines the skip distance Fading Fading happens when signals return to earth by two or more separate paths and cancel each other out. Aircraft, Mountains and ionospheric layers may also reflect part of a signal while the other part of the signal takes a more direct path
- 30. Propagation Terms 3Propagation Terms 3 MUF (Maximum Useable Frequency) The MUF varies with solar activity and time of day and is the highest frequency that will reflect off the Ionosphere. If the frequency used is too high, it will pass through the layers and disappear into space. e.g The 24Mhz – 28Mhz example Ionization The ionization level of the ionosphere reaches it’s minimum just before sunrise The Grayline That hour at Sunrise and at Sunset when the DX magic happens!
- 31. The Grey line is RealThe Grey line is Real
- 32. How the Grey line worksHow the Grey line works
- 33. SV3AQR Beacon on 28,123 Mhz. Note the 10Db increase at the beacon's dusk Not every band, location or terminator path behaves the same way. Signal strengths along the Grey LineSignal strengths along the Grey Line
- 34. Understanding Radio Propagation is a bit like A blind man in a dark cellar searching for a black cat that isn't there. It's a highly nebulous process! That damned cat is here somewhere!
- 35. Software that will help you work the rare ones W6EL Propagation Prediction program: It’s free and will tell you when there may be a path opening to where you want your signals to go. DX Atlas: This program will tell you everything about the actually path of your signal. Better still, it will tell you the exact time you will have to work “The Gray Line” Aids ( No, not those aids! )Aids ( No, not those aids! )