I find the markers in the IF window more useful than those in the
main window. If you set the averaging in the IF window to 60 or
100, then the numbers are smooth enough to use for sun noise
measurements on microwave bands. You can reduce the jumpiness of
the on-screen measurements by changing the averaging on the main
waterfall to 20 or so, and smooth out the S meter readings by
changing the update interval from the default 60 ms, but I don't
know if that does an averaging process, or just discards the
intervening measurements!
For anything really clever, it is probably easier to work on the
waterfall data which is streamed out of the extio port, and do the
analysis using some custom code.
Ivo's post prompts me to air my own comment on the SW2
S-meter.
I'm not an expert user. There are two radio/software
combinations available to me whose S-meter by reputation
provides a well-defined, accurate and reliable total (not peak)
power measurement: RSP1A+SDRuno and S2+SW2.
My use of S-meter readings includes:
(a) meaningful logging of received signal strength, for
signals of any type
(b) comparative assessment of changes to system components
(e.g. antenna mods)
I have no specialised signal measurement equipment, hence the
reliance in (b).
In those activities (for my comfort) there are two
enhancements to SW2 that could help considerably:
(1) showing Marker 1-type data in the "desert" next to the
S-meter
(2) calculating/displaying an average S-meter reading as well
as SNR
The argument for (1) is that bringing up marker data is
time-consuming. For (2) it is that even relatively stable
signals show fluctuations that cannot accurately be averaged by
eye.
Refinements could be:
(3) user control over averaging period
(4) calculating/displaying the S-meter variance (standard
deviation)
I would find (3) especially useful for slow fading, and (4)
as a measure of fading severity.
