5. Summary of results

The algorithm for calculating the oscillator spectrum does not give sufficient precision with the list of integration frequencies by default. In fact, the input signal has frequency content up to \(50\mathrm{Hz}\), while the list of frequencies by default for the SPEC_OSCI keyword from CALC_FONCTION stops at \(\mathrm{35,5}\mathrm{Hz}\).

In this example, it is therefore necessary to modify the operator’s input frequency list. It is therefore necessary to be attentive to the spectral content of the signal and not to blindly trust the default values (the default list is well suited to the regulatory signals that are usually encountered in France whose cutoff frequency is lower: of the order of \(20\) to \(30\mathrm{Hz}\)). Likewise, if the input signal is characterized by a particularly fine frequency discretization, it may be appropriate to use a list of frequencies defined accordingly for the calculation of the oscillator spectrum. Here again, the values by default may prove to be unsuitable, and induce a loss of precision in the results thus calculated.