auto gain issues

[VirusPilot]

As discussed I am experimenting with auto gain - initial results are not fully convincing. Some nearby transponder signals are not triggering any gain change at all, sometimes a reduced gain won't recover although no signal is around. I have compiled a more verbose output version but this line here won't compile:

readsb/readsb.c

Line 830 in bfc4a0b

//fprintf(stderr, "%9s gain. noiseLow: %5.2f %% noiseHigh: %5.2f %% loudEvents: %4lld\n", action, noiseLowPercent, noiseHighPercent, (long long) loudEvents);

as action is not defined. Can you clarify? Are there any other debug messages that I could use? The receiver is located on top of our airport tower.

[wiedehopf]

Replace action with reason.

But this should be sufficient for debugging:
--gain=auto-verbose

Which gain setting are you using exactly?
Some SDRs might behave differently i suppose.

Reduced gain might not go back up if there is a lot of noise.
If there is a lot of noise, increased gain is unlikely to be useful.

[VirusPilot]

I have been using standard gain settings for the most part but e.g. reduced loudThreshold . Still not fully understanding how all auto-gain values correspond to dBm values so that they could be adjusted based on measured values. Btw. I am using RTLSRD v3 silver sticks.

[wiedehopf]

While you could translate to dB values it would still not be intuitive.

Decreasing loudThreshold seems like the correct thing to do in your situation.

Pushed a version that has that extra debug output fixed up.

Some nearby transponder signals are not triggering any gain change at all.
Are you saying the SDR is receiving data from them? Then you really don't need to reduce gain?