Screenshots of VOACAPVOACAP Quick Guide: Home
VOACAP (for point-to-point circuit analysis) and VOAAREA (for area coverage analysis) are extremely powerful tools for professional-grade HF circuit predictions. Contrary to the common belief, the VOACAP user interface is often simpler than that of many other HF prediction software, and the result graphs and coverage maps usually outperform those of the competing tools. There is no competition, however, as VOACAP is free!
Below you will catch a glimpse of the many exciting features VOACAP can offer.
The Input Screen
This is the input screen. Please note that there is only one screen, it cannot be much simpler than that.
HF Spectrum vs. Time Graphs
This is the signal-to-noise (SNR) graph as a function of 2-30 MHz and time, for a circuit from the United Nations in NYC to Cape Verde in Africa. Besides this graph, there are 19 additional graphs that describe various properties of this particular circuit, such as signal power at receiver, and the optimum radiation angle of the transmitter antenna.
User-defined Frequencies vs. Time Graphs
This is the 24-hour analysis graph of the given output parameter on user-defined frequencies from the UN to Cape Verde, Africa. The user can choose from 23 output parameters; shown here is the parameter SDBW, i.e. median signal power at receiver site. By looking at the graph, the user can easily understand the behaviour of the lower frequencies and higher frequencies at the different times of the day on the given circuit.
User-defined Frequencies vs. Distance Graphs
This is the distance graph of the given output parameter on user-defined frequencies from the UN towards Cape Verde, Africa at 01 UTC. The distance graph shows how the user-defined frequencies start to propagate away from the transmitter towards the receiver site. The user can choose from 23 output parameters; shown here is again the parameter SDBW, i.e. median signal power at different distances from the transmitter.
Area coverage maps are perhaps the most exciting part of VOACAP. The coverage maps are made with the VOACAP companion program, VOAAREA. Coverage maps are produced by calculating a huge amount of point-to-point circuits from the transmitter to the geographical area defined by the user. A 31x31 matrix, as shown here, means that the coverage map was created from 961 point-to-point circuit calculations. When the geographical area is large, a better resolution may be needed. VOAAREA allows a matrix of 361x361 (130,321 P-to-P circuits) to be calculated at maximum.
This particular coverage map shows the median Maximum Usable Frequency from Finland to the rest of the world in November 2005 at 10 UTC. A total of 23 output parameters can be plotted on the map.