R&S FSH
Spectrum Analyzer Mode
Performing Spectrum Measurements
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3.1.10 Working with the Spectrogram Result Display (R&S FSH-K14/ -K15)
With option R&S FSH-K14 or R&S FSH-K15, you can view measurement results in a
spectrogram.
The spectrogram result display shows the spectral density of a signal in the frequency
domain and over time simultaneously.
Screen layout for the spectrogram
1
Result display
2
Marker and time line information
3
Spectrum result display (optional)
4
Marker/ delta marker (vertical lines)
5
Spectrogram
6
Time lines T1 and T2 (horizontal lines)
7
Scroll direction
8
Spectrogram softkey menu
Like other result displays, the horizontal axis represents the frequency span. The
vertical axis represents time. Time in the spectrogram runs chronologically from top to
bottom. Therefore, the top of the diagram is the present. A third dimension shows the
amplitude for each frequency by mapping different colors to every power level. The
result is therefore a two dimensional diagram.
The color the R&S FSH assigns to a power level that was measured depends on:
● the color table you have selected
● the spectrogram reference level
● the spectrogram level range
The spectrogram consists of horizontal lines, each one pixel high, that are called
frames. In the default state, a frame is added to the spectrogram after each sweep.
This means that the amount of data in a frame depends on the sweep time. As the
spectrogram in the R&S FSH runs from top to bottom, the outdated time line(s) move
down one position, so that the present frame is always on top of the diagram.
Therefore, the sequence of frames is chronological.
