¶ 相关文件：PSD_RTD
¶ 1. Profile
This provides the same functionality as Real Time Display (or RTD) Power Spectral Density (or PSD) in DCS. That is it shows the PSD of signals in real time. Note that DCS also had a RTD Sine Sweep component. This is not currently available in Pulsar but could be added with a few days work now that RTD PSD is implemented.
The PSD of multiple signals can be viewed.
The update rate is configurable.
The sample rate is configurable.
The PSD graphs can be saved and printed.
（图片命名：DFT_02 DFT Module of Pulsar.png）
PSD_RTD_01 Spectrum Analyser.png
¶ 2. Psd Algorithm
Psd Algorithm
DAP uses the standard Matlab function with Hanning windowing and 50% overlapping :
[Pxx,F]? = PSD(X,NFFT,Fs,WINDOW,NOVERLAP)
where NFFT is the FFT block size defined in the menu Configure -> Global Data of DAP.
Fs is the loggingrate of the file.
WINDOW is set to NFFT
NOVERLAP is set to NFFT/2
The PSD is then normalised by the Nyquist frequency, ie:
Pxx=Pxx/(Fs/2)