The tools provided by this web application enable users to predict available frequencies, signal levels and corresponding reliabilities for High Frequency (HF) circuits for user defined paths and times. Predictions are performed using the ITURHFPROP application (A software method for the prediction of the performance of HF circuits in accordance with Recommendation ITU-R P.533-13) provided by the ITU.
Three prediction modes are supported:
Area
Predicts geographical coverage for a given site at a specified time and frequency.
Point-to-Point
Predicts link performance for a specified path over a 24 hour period in a given month.
Surface
Predicts link performance for a specified path over a 24 hour period for multiple months. Monthly predictions are created by determining the maximum predicted value of the specified parameter (e.g. reliability) for each hour. The monthly predictions are then 'stacked' to provide a 3D representation of link performance over an extended time period. The resulting image is interactive and may be rotated/scaled using a mouse, allowing users to fully explore the dataset.
Useful References
The following material may be of interest when researching HF Propagation and ITURHFProp;
ITU-R P.1148-1 , 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 F.240-7 , Signal-to-Interference Protection Ratios for Various Classes of Emission in the Fixed Service Below About 30 MHz, Recommendation ITU-R F.240-7
ITU-R F.339-8 , Bandwidths, Signal-to-Noise Ratios and Fading Allowances in HF Fixed and Land Mobile Radiocommunication Systems, Recommendation ITU-R F.339-8
Development of this web application has been made possible with the generous assistance of Chris Behm and George Engelbrecht, creators of the ITURHFPROP application. In addition, Bill Ingram provided valuable assistance on the construction of antenna input files.
I would also like to thank John Stephen Dumadag, REE for help with the NEC antenna modelling.
Jari's VOACAP Site was a priceless source of inspiration for the main user interface.
Translations
I'm grateful for the efforts of the following for their help with translating the site;
Arabic (ar): Rami Saadeh
Finnish (fi): Jari Perkiömäki (OH6BG/OG6G)
German (de): Heribert Lennertz (7Z1HL / DL8KAY)
Italian (it): Marco Colombo (IU2DXF)
Spanish (es): Javier Albinarrate (LU8AJA)
Open Source Tools
This site uses uses a number of open source tools for which I'm very grateful to the following;