↑ Forecasting tools for HF radio propagation

Edited by Doron Tal, 4X4XM

The MUF300 map is user-friendly forecasting tool for predicting real-time HF radio propagation. However, because it is based on a simplified model that does not account for geomagnetic storms and blackouts caused by Elevated X-ray Flares and/or Proton Ejections, the estimation's accuracy is insufficient for commercial radio service purposes. Other reasons for low ionospheric parameter accuracy include insufficient measurement coverage of the Earth and errors in estimating ionosphere parameters from vertical sounding data.

There are several hundred ionosondes that can take measurements. The vast majority of these are concentrated in a few areas of the world, with large areas remaining unmonitored. As a result, that map is an interpolation. While the guessing process is fairly accurate in areas close to MUF measurement stations, the uncertainty in areas far from any measurements is much higher. Only the numbers within the colored dots scattered across that map represent actual measured data.

The idea to predict HF propagation based on Ionospheric Monitoring and Prediction System has been described years ago. See for example this PDF.

The following applications can forecast HF radio propagation (a few days in advance):

  1. VOACAP (Voice of America Coverage Analysis Program): This is a widely used program that predicts HF radio propagation for both point-to-point and area coverage. VOACAP uses historical solar and ionospheric data to predict the radio propagation over a specific path.
  2. ITU-R-HF-Prop: This is an ITU-R recommendation that provides a method to predict the performance of HF radio systems in a wide range of propagation conditions. The ITURHFProp software, written by G4FKH and HZ1JB, is based on the ITU-R P.533 method and uses a probabilistic approach to estimate radio coverage.
  3. SWPC - NOAA Space Weather Prediction Center provides a variety of space weather services, including forecasts of HF radio propagation. The SWPC uses data from various sources, including ground-based and space-based observations, to predict the ionospheric conditions and their impact on HF radio communications.
  4. SWS - Space Weather Services of the Australian Government Bureau of Meteorology provides real-time and near-real-time information on the state of the ionosphere and predictions of ionospheric conditions. This service measures and monitors ionospheric parameters like electron density, electron temperature, and ionospheric irregularities using a combination of ground-based and satellite-based sensors. All of these can be used to predict HF radio propagation.

Each of these tools/services has advantages and disadvantages, and the tool selected will be based on the user's specific needs and requirements. It should be noted that none of these services can provide perfect predictions because radio propagation is affected by a number of variables that are difficult to predict completely.

You may find more detailed information in the main webpage, here. See also an index for HF Radio Propagarion.