Graphical Circuit Prediction
After you have set all the circuit parameters in the VOACAP main screen, or if you have run a textual circuit prediction, it is time to run the analysis in a graphical mode.
Our data example is again from the circuit of Pori (Finland) - Johannesburg (South Africa). Choose Graph from the Run menu (abbreviated later in these web pages as Run > Graph). A new window will open, containing all the available output parameters:
The graphical charts provide a nice overview of the parameters on the frequency/time scale. To view the exact details of the values, click anywhere on the chart, the details appear below the menu bar:
While in a parameter output window, another parameter can be chosen by clicking the Parameters menu. The frequency scale (on the left side) can be changed from the Scale menu. If you wish the window to be pasted into another program, click the to Clipboard menu. To print the window, choose from the Print menu.
Some of the most prominent parameters to look at are SNR, REL and SNRxx. Below are those parameters from our circuit. The thick black line that runs through the chart is the median MUF.
SNR (aka SNR50)The SNR values (in dB-Hz) that can be maintained 50% of days (15 days) in the month.
REL (Circuit Reliability)The percentage of days in the month when the SNR (SNR50) value will equal to or exceed the REQ.SNR.
SNRxx (aka SNR90)The SNR values (in dB-Hz) that can be maintained 90% of days (27 days) in the month.