30 days solar cycle
activity.
Solar activity forecast for next 27 days
Estimated planetary K-index.
Near real time MUF map.
The following map shows Maximum Usable
Frequencies (MUFs) for 3000 kilometer radio signal paths. More
importantly, the current sunspot number (SSN) and Planetary A-index are
updated every 30 minutes on the bottom of this image. Additionally, the
grey line position, auroral ovals, and sun position are provided.
Near real time E layer critical frequency map.
The
following image is a recent high-resolution global map of E-layer
critical frequencies. This corresponds to the maximum radio frequency
that can be reflected by E-region of the ionosphere at vertical
incidence (that is, when the signal is transmitted straight up into the
ionosphere). It is also a map showing the current location of the
auroral ovals, the sunrise/sunset terminator and the regions of the
world where the sun is 12 degrees below the horizon (which estimates the
gray-line corridor where HF propagation is usually enhanced)
Radio communicators most often do not
want their signals to spend very much time in this region of the
ionosphere. Signals which are reflected within the E-region spend the
greatest time in the E-region and are accordingly attenuated the most.
Signals that exceed the E-layer
critical frequency (and are vertically incident) will penetrate the
E-region and travel toward the F-regions. Signals that are below the
critical E-layer frequency will always be reflected back to the Earth.
|
|
