The 3D FFT filter block draws three dimensional power spectrums at real time.
Configuration
The config button, which is on the top of the 3D FFT window, opens the following configuration dialog.
Parameters
Frequency resolution
The frequency resolution tells the resolution of the frequency axis. The resolution is given as powers of two because the Fast Fourier Transformation (FFT) algorithm is used.
Number of lines
The number of lines parameter tells how many frequency graphs are drawn in the time axis.
Origo position
The Origo position gives the position of the origin. The origin position is given as percentages from left and top. For example 50/50 means that the origin is in the middle of the 3D FFT window area.
Slot Average
The Slot average tells how many 1024 long sample slots are averaged before the graph is plotted.
IIR Factor
The IIR factor uses the following formula to average frequency vectors.
fi = a * fi * (1-a)*fi-1
where a is the IIR factor
