Background

For most non-GSO systems, all the necessary EPFD runs and their associated parameters are generated by the software. In particular:

• The worst-case geometry (WCG) algorithm calculates the positions for the reference GSO satellite and its Earth station by determining the geometry that would result in the highest single entry EPFD with the largest likelihood
• The run time calculation determines the step size and run duration to ensure statistically significant results.

The algorithms to calculate the WCG and run time and step are given in detail in Recommendation ITU-R S.1503-2.

However there are times when it can be useful to consider alternatives, for example to look at geometries that where there could be high long-term EPFD. This can be achieved by changing the run parameters, as described in this section.