Power Spectral Density Slow Method (Application).
Application pss is to calculate the power spectral density of a time series, by using a direct slow Fourier algorithm. It requires 1 input series. It is run in the Question/Answer user interface by typing:
[n]Xronos> pssin the Partial Question/Answer user interface by typing:
[n]Xronos> pss [series1]and in the Command-Driven user interface by typing:
[n]Xronos> pss[/qualifier1/qual2/... etc] [series1]
The newbin time must correspond to an integer multiple of the maximum bin time. The default newbin time is either the maximum bin time (if fewer than 4096 newbins are expected) or the integer multiple of it which will produce a single interval with number of newbins <4096. The average count rate in each interval is subtracted from all newbins, and gaps and rejected newbins are replaced with zeroes, before the power spectrum is calculated.
The power spectral error bars are obtained either by propagating the theoretical error bars of the spectra from individual intervals (from the relevant chi-square distribution) or by evaluating directly the standard deviation of the average of the power in each frequency bin from different intervals. This depends on whether the specified number of intervals per frame is, respectively, smaller or larger than the value of global parameter number 9 (default =5).
Error bars are plotted by default only if two or more power spectra are averaged. Sidelobes and other effects introduced by windows, data gaps etc. can be studied by analysing the exposure profile of the time series, by setting global parameter number 10 to 1.
The analysis normalisation flag, specified by global parameter number 11 has the same meaning as in application psd.