ips-tindex-predictions -- SWS (IPS) Observed and Predicted T Indices
About ips-tindex-predictions	English (USA)
A table of observed and predicted values for the SWS T Index. The T Index is a measure of the behaviour of the F-layer of the ionosphere and is used as an input for the SWS HF frequency prediction program ASAPS. The T-index is calculated from the vertical MUF (foF2) obtained from SWS ionograms combined with the SWS world map grid point data. The grid point data form the SWS world maps of foF2, there are 576 maps, for two ionosheric levels (T=0, T=100), 12 months, and 24 hours. An foF2 observation can be converted into a Tindex by interpolation/extrapolation of the line obtained from the maps at a geographic location ie two map T,foF2 value pairs and the observed foF2, then read off the corresponding T value. The SWS maps are not available for distribution, as they are part of the intellectual property of SWS. More background information on the SWS Tindex is available here. The Tindex is predicted over a coming solar cycle to provide a long term ionospheric index trend for HF communicators. This report is usually issued soon after the start of each calendar month. Ionospheric data is available for download from the SWS World Data Centre at: SWS WDC Ionospheric Data To see the collection of prior postings to the list, visit the ips-tindex-predictions Archives.
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