I am trying to understand why my message rate dropped. Since some time I am using an Airspy mini and my messages rate went up to 1800+
The last few days, even today with no clouds at all, the best message rate was 1386, still a little bit more than with my RTL-SDR dongle. But far from the 1800+
I have been reading in all kinds of threads in this forum, but cannot find an understandable answer.
Is your LNA working properly?
Your green area seem to be low
This is mine with active Uputronics and gain set to 19. Have you tried it with this setting as well?
The number of aircrafts has increased a little bit.
I did try to set gain to 19, but will do it again and see if something will change. First impression, only the weakest signal goes from -30 to -25. The green area just moves the same amount.
From what I see in your graphs the green area stays as wide with gain 18 and 19, just “moved” up.
But it can be that I do not interpreted that correctly
Will figure out if my Uputronics is working properly, but as said did not change anything. Did not disconnect or something.
From what to what? We need absolute numbers, not relative statements.
For my peaks of 1600 msg/second i need at least 90 aircraft with ADS-B positions.
All below is approx. 20 messages per aircraft which is also shown in the graphs of your instance. Check if these values have been changed as well.
So one possibility is that there is interference and it got worse.
If you have a blue FA filter, you can try it in front of the uputronics.
Really it’s hard to say why people have different results.
What pi do you have and what threshold do you run for airspy_adsb?
As in the -e value.
It’s explained in the settings file.
Reading will increase knowledge. Well sometimes it takes repeated reading and googling and stuff like that
#-e: preamble filter sensitivity, values: 0.1 to 11.0 (higher values increase CPU load and can improve detection)
There should be the airspy CPU load in the graphs, increase -e step by step until you get a load of around 80% for that graph
All the help is very much appreciated. @wiedehopf
Your githup airspy is bookmarked and do not worry I read it over and over. Did not want to bother you before reading it
Just because your setup doesn’t change, doesn’t mean the weather, interference and air traffic doesn’t change.
All that can affect the message rate.
Say there is a mobile phone tower that overloads the uputronics LNA while it’s transmitting.
Normally it’s not too busy and not sending with a high duty cycle.
Then it gets used more and the duty cycle increase.
Thus your reception suffers in more time slices than before.
Basically your station isn’t as sensitive when that transmitter is on but it’s not on all the time but switches on and off really fast.
In Europe the message rate can also change considerably depending on what responses are being requested by ATC interrogations. I have occasionally seen a sudden drop or increase in message rates that aren’t attributable to any other changes in hardware or software.
I have been running my system with the new settings for two days. It seems there is hardly a difference with the “old” settings.
Old:
Gain 18
Sample rate 12
OPTIONS= -v -f 1 -b
