Dispatch of Canada
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 our 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 kilometer 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 kilometer 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 MUFs 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 MUFs.
The radio auroral zones are typically displaced equatorward from the optical auroral zones (or the regions where visible auroral activity can be seen with the eye).
The great-circle signal path from the Eastern United States to Tokyo Japan is shown along with the distance of the path (in km) and the great-circle bearing from the U.S. to Tokyo (in degrees from north).
If this signal path crosses through the green lines indicating the position and width of the radio auroral zones, propagation will be less stable and degraded compared to if the signal never crossed through the auroral zones. Using your mouse, PROPLAB-PRO will let you plot the great-circle paths and azimuths between any two points while this display is continually updated.
Near RealTime MUF World Map
Get the latest Maximum Usable Frequency MUF worldwide prediction updated
at this RESEARCH project
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Last Modified September 25, 2011