Receiver Mode
R&S
®
ESRP
128
User Manual 1175.7445.02 ─ 08
Each color in the spectrogram corresponds to a particular power level that is shown in
the color map in the title bar of the result display. The color the R&S
ESRP assigns to
each power level depends on:
●
the color scheme you have selected
●
the (customized) color mapping settings
In the default configuration, the R&S
ESRP displays low power levels in 'cold' colors
(blue, green etc.) and higher power levels in 'warm' colors (red, yellow etc.).
For more information, see
Data processing
Now that the data is available, the R&S
ESRP processes the data to display it in the
spectrogram result display.
To understand the structure and contents of the spectrogram, it is best to look at it in
combination with the scan or IF analysis result display. The data that is shown in the
spectrogram is always based on the data of the scan or IF analysis trace.
The spectrogram is made up out of a number of horizontal lines, each one a pixel high,
that are called (time) frames.
●
When you use a spectrogram in combination with a scan, each frame corresponds
to a single sweep of the frequency range you are scanning.
●
When you use a spectrogram in combination with IF analysis, a single sweep may
consist of several frames. The exact number of frames depends on the measure-
ment time of the bargraph.
In the default state, a frame is added to the spectrogram after a sweep is done. As the
spectrogram in the R&S
ESRP runs from top to bottom, the outdated frame(s) move
down one position, so that the most recently recorded frame is always on top of the
diagram.
The number of frames the R&S
ESRP can display simultaneously is only limited by the
vertical screen size. The number of frames the R&S
ESRP stores in its memory is big-
ger. The maximum number of frames you can record is 100.000. The actual number,
however, depends on the measurement configuration. With markers, you can navigate
to any frame that has been saved.
Note that the contents of the spectrograms for scan and IF analysis are independent
from one another: the R&S
ESRP saves the data you have already recorded and the
current configuration when you switch to another result display. It keeps the data until
you start a new measurement or the capture buffer is full.
5.1.6.2
Color Map
Colors are an important part of the spectrogram. Therefore, the R&S
ESRP provides
various ways to customize the display for best viewing results.
You can access the Color Mapping dialog via the "Color Mapping" softkey or by tap-
ping on the color map. For the spectrogram the R&S
ESRP maps power levels (dBm).
Measurements and Result Displays
