Propagation Tools
It's hard to know when certain parts of the RF spectrum are open to signals and how the atmosphere is affecting them, or how long they might last for, luckily there are now quite a few handy tools and charts around that can predict, some very accurately, what parts of the bands are open and when they will be at the very best.
Using these 'tools' you will be able to better prepare yourself for when these conditions will be at there best, or to quickly see what the conditions are like at any given time of the day or night, we hope to add more tools as we find them so as you can arm yourself with the knowledge of what's about.
All images & Tools automatically update every 5 minutes
Magnetic Field:
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Solar X-Rays
Geomagnetic Field
Above tools supplied by N3KL |
| Above tool supplied By: The Space Environment Centre |
For a current VHF/UHF Tropospheric Ducting Forecast for Australia or for the rest of the world please see the following informative website maintained by William Hepburn: TropoDucting.
Ionospheric Total Electron Content (TEC) Map:
Courtesy IPS Radio and Space Services © Commonwealth of Australia 2008
This near real-time ionospheric total electron content (TEC) map is produced at IPS by using the IRI-90 ionospheric model with real-time foF2 data observed at the ionosonde stations distributed in this region. The map shows colour contours of TEC in units of 1016 electrons/m2.
The data on this map can be used to get an estimate of the corrections to be applied to satellite navigation measurements to account for the extra delay in the transmission of the radio signals between the satellite and a receiver on earth due to the presence of the ionosphere.
Near-Real-Time MUF Map:
Using This Map:
This is a highly informative map that can be used by amateur and professional radio communicators to determine maximum usable frequencies (MUF) for any world-wide path at the indicated UTC (Zulu) time.
RED contour lines will appear superimposed on the MUF map if x-rays reach levels capable of producing short wave fadeouts on sunlit paths. When this occurs, the red contour lines represent the highest frequency (in MHz) that may be absorbed by the enhanced solar flare x-rays. Use this information together with the new X-ray Absorption Map to determine what frequencies and paths may avoid affects of radio signal absorption during x-ray flares.
The MUF for any 3,000 kilometre path can be determined by finding the midpoint (or half-way point) of the path and examining the MUF at that midpoint on the map by finding the labelled MUF contour value. All contours are given in MHz.
For 4,000 kilometre paths, multiply the given contoured MUF values by 1.1. The MUF for the given 4,000 km path is then determined at the midpoint of the desired path. For longer path lengths, divide the path into equal 3,000 or 4,000 km segments and compute the MUF's corresponding to the two midpoints that are 1,500 or 2,000 km from each end of the path. Then select the lower of these two MUF's.
For more information about the MUF Map and it's usage please see the Space Weather site.
Solar Activity:
Recent detailed solar activity charts and images can be found at the Lockheed Martin Solar And Astrophysics Laboratory here.
Solar activity chart for the last month, updates every 24 hours:
Courtesy of IPS Radio and Space Services © Commonwealth of Australia 2008
HAP Chart (Hourly Area Prediction):
The following HAP (Hourly Area Prediction) chart is updated every hour and is a guide to frequency selection for HF communications between mobiles and a specific base, the base in this chart is Hobart and it gives a good indication on frequencies for communication with the base by mobiles at any given hour, these charts are based on real time data.
Ledgend:
'dash lines' - If present, these delineate areas of unlikely communication. Poor communication areas which can result from one or more of the following conditions:
- the Absorption Limiting Frequency (ALF) is higher than the Optimum Working Frequency (OWF).
- the ALF exceeds the highest frequency in the user's frequency set.
- there is no suitable frequency from the user's set that is between the OWF and ALF.
For other bases throughout the Australasian region please got to the following site and choose a new base from the drop down menu to obtain the above data for the chosen base: http://www.ips.gov.au/HF_Systems/1/1/1
HF Spectrum Display 1 - 30MHz:
Click the link below to have a look at the HF spectrum from 1 to 30 MHz as seen by the IPS Culgoora Observatory, near Narrabri in northern NSW, Australia. Horizontal lines across the display are occupied HF channels in use by the general public, during local daylight hours solar flare activity can cause HF (shortwave) signal strengths to not be as high, they will appear as a break in the occupied channels on the display, also vertical strokes on the display can appear during local thunderstorm activity.
The antenna used is a simple 10 metre long broadband dipole, above 28MHz the antenna gain performance does drop off which shows a decrease in signal strength above and beyond this frequency.
The display updates every hour and can be viewed here.
The above HAP Chart and Spectrum Display is courtesy of IPS Radio and Space Services © Commonwealth of Australia 2008.
If you have any handy propagation tools to add or know of some that we don't have then please let us know so as we can add them here.