This site would not be available but for the kind co-operation of the ITU through the guise of Chris Behm, the compiler of ITURHFProp. The program calculates the HF path parameters in accordance with ITU Recommendation ITU-R P.533-14. Predicted sunspot numbers used on this site are gathered from NOAA NWPC.
Thanks are due to James Watson, M0DNS/HZ1JW whose hard work developed the Area Coverage page. James has continued since with the correction of many bugs and with further development of the site.
The Point-to-Point page and workings were developed by Mark Lawrence, M0WMT. His knowledge and creativity; designed, developed and wrote the code for this page.
The algorithms used for the NVIS calculations can be readily found on the Internet and documented in various texts, including - 'Near Vertical Incidence Skywave Communication' by LTC. David M. Fielder and Maj. Edward J. Farmer. The suggested Ionograms are courtesy "University of Massachusetts, Lowell".
The following list may be of interest to those researching HF Propagation and ITURHFProp:
ITU-R P.533-13 (2015), Method for the prediction of the performance of HF circuits, Recommendation ITU-R P.533-14
ITU BR Indices (2016), Circular of Basic Indices for Ionospheric Propagation, Latest
ITU-R P.371-8 (1999), Choice of Indices for Long-Term Ionospheric Predictions, Recommendation ITU-R P.371-8
ITU-R P.372-12 (2015), Radio Noise, Recommendation ITU-R P.372-12
ITU-R P.1148-1 (1997), Standardized Procedure for Comparing Predicted and Observed HF Sky-Wave Signal Intensities and the Presentation of Such Comparisons, Recommendation ITU-R P.1148-1
ITU-R P.1239-2 (2012), ITU-R Reference Ionospheric Characteristics, Recommendation ITU-R P.1239-2
ITU-R F.240-7 (2006), Signal-to-Interference Protection Ratios for Various Classes of Emission in the Fixed Service Below About 30 MHz, Recommendation ITU-R F.240-7
Lane, G. (1997), Required Signal-to-Interference Ratios for Shortwave Broadcasting, Radio Science, 32(5), pp2091-2098