Graphs for dump1090 -- my version with install script

Now my system has settled down (and before I start tinkering with it :crazy_face:) I was wondering what the experts out there might make of my graphs?

It would be good if I could solicit your analysis/opinions and then maybe in another week or so after I change the AIrNav FlightStick for the FlightAware ProStick Plus I could be so cheeky as to post my graphs again to compare them both?

My RadarBox station ranking has been pretty steady at 8 in the UK/120 Globally so that should be pretty easy for me to keep my eye on but although I can loosely interpret the graphs it would be better to ask the opinions of those who know!

The Gain on dump1090-fa is set to -10 if that makes any difference and I did try it on what would be effectively the next setting down 49.6 which reduced the messages >3dB from a possibly too high(?) 13% to a possibly too low(?) 0.3%

Thanks & kind regards,

If I look at the noise floor with your gain setting at -10 (AGC on) and amount of signals >-3dBFS, I think you should reduce your gain. Most probably the manual gain of 49.6 was still too high, causing overload. The easiest solution is to install Wiedehopf’s automatic gain script, and let it do the gain tweaking for you. Do you have a pre-amp in the chain?

So … with those numbers the automatic gain script would probably switch back and forth every night.

Manual gain change then until the right gain is found. I would suggest running a scan to see if the system gets overloaded by some out-of-band signals, like a cell-phone tower close by.

Thanks for the reply hellhound604 & wiedehopf,

Well I did reduce the gain to 49.6 and as I said the percentage of messages >3dB went down to 0.3% which as I understand it is much lower than the ‘target’ of 5% and apart from the expected signal level drop didn’t seem to affect things much at all?

But at the same time my ranking dropped although this could have been due to other factors such as weather, number/location of aircraft etc.

And if the signal level is still below zero when the gain is set to -10 would that indicate it is not overloaded? :confused:

There is no external pre-amp in the chain but I believe the FlightStick may have one fitted along with a filter not unlike the ProStick Plus? The antenna is a Watson Radar Extender connected by @7m Westflex 103 and has proved itself over many years although that’s not to say its performance hasn’t deteriorated over time.

How would I run a scan to check for out-of-band signals although judging by my poor mobile reception this might not be an issue! :stuck_out_tongue_winking_eye:

Thanks & kind regards,

There is a whole thread about it here:

[Do I Need A Filter?]


That’s really not so much a target as it is an orientation.
It’s likely not a major difference in your case.
Well you might lose some very close by positions for low flying aircraft with the higher gain (which happens very rarely and thus doesn’t affect stats at all).

Switching to the FA Pro+ is actually very likely gonna tell you if you have strong interference / need a filter for it.
The AirNav flight stick has the filter before the LNA, the FA Pro+ has the LNA before the filter and is thus more sensitive to both signals and overload of the LNA.

Thanks for the replies guys…I have read most threads covering dump1091, Airspy/FlightStick/FlightAware, filters, etc. that I could find with up to 800+ posts per thread and as is usual for me it seems to raise more questions than answers!

I haven’t yet had the courage to swap the FS for the Pro+ but will finally get round to it and will update this thread on my findings however unscientific they may be!

Reading between the lines I’m guessing the FS has the filter before and the FA Pro+ after?

Thanks & kind regards,

This is an amazing tool, thank you @wiedehopf for taking your time to get it completed.

I just have a question or two, how can I interpret this graph? Is my gain too high (currently 40 and when running <awk “$(cat /run/dump1090*/stats.json| grep total | sed ‘s/.accepted":[([0-9]).strong_signals":([0-9]).*/BEGIN {printf “\nPercentage of strong messages: %.3f \n” , \2 * 100 / \1}/’)”> it returns 25).

Thoughts on optimizing gain

OK, I believe I’ve read it once or twice (thus the command above :slight_smile: )

I will decrease the gain and see what we’ve got.

Thank you for confirming what I was thinking.

Well the 2nd post in that thread has quite clear instructions and even recommends different percentages depending on what you want.
Some people recommend going to 0.5 % or 0.1 % (usually people who don’t care too much about planes far away)

So in essence, by lowering the gain, should I be seeing more messages per plane (also messages per second) and losing the distance the planes are seen.

Is my understanding correct or am I way off?

If you lose any range depends on multiple factors it usually only starts at a certain gain that is individual to each installation.

Depending on if an aircraft is currently overloading the receiver you will gain messages per second but only for that specific aircraft.
The aircraft with the strongest signals are close by and lower altitude.

If you have massively too much gain and reduce you will gain messages per second for a lot of aircraft.

Understood, just want to add that I do have a preamp in the mix with rtl-sdr bais-tee enabled.

CoCo antena with 5 segmesnts, pre-amp and rlt-sdr. I should have mentioned that before.

Actually that’s only relevant for the absolute gain value.
If you look at percentage of strong messages and adjust according to that it’s irrelevant.


Thank you as always.

Re: " Installation / Update to current version:

sudo bash -c "$(wget -q -O -"

Great stuff; well beyond my pay grade.

I get a 404 not found when trying urls .../graphs1090 and .../perf.  Help?

Install seemed to go okay via putty and I reset default to default (for argument's sake), restarted piaware 4.0.  

Can't seem to nail down the error when everything else works fine.  The node pings fine and data is still transmitted to fa.


Are you sure it’s the right IP, can you post the full URL you’re trying?
I suppose /dump1090-fa works?

What is the output if you run

sudo bash -c "$(wget -q -O -"

Also can you show the output for the lighttpd commands here:
GitHub - wiedehopf/graphs1090: Graphs for dump1090 (based on dump1090-tools by mutability)

My node is static outside the dhcp range. dump1090-fa does work.

sudo bash -c “$(wget -q -O -”
returns the prompt:

I have a router stability problem more often than anything else.

Running sudo systemctl status lighttpd returns:

pi@piaware:~ $ sudo systemctl status lighttpd
● lighttpd.service - Lighttpd Daemon
Loaded: loaded (/lib/systemd/system/lighttpd.service; enabled; vendor preset:
Active: active (running) since Wed 2020-12-30 11:38:50 UTC; 1 months 23 days
Main PID: 561 (lighttpd)
Tasks: 1 (limit: 4915)
CGroup: /system.slice/lighttpd.service
└─561 /usr/sbin/lighttpd -D -f /etc/lighttpd/lighttpd.conf

I will try to get them to github for you but basically:

sudo bash -c "(wget -q -O -" pi@piaware:~ ls /etc/lighttpd/conf-enabled
50-piaware.conf 88-dump1090-fa-statcache.conf 89-dump1090-fa.conf 89-skyaware978.conf

– Logs begin at Thu 2021-01-28 19:26:00 UTC, end at Mon 2021-02-22 13:45:29 UTC. –
Feb 22 13:41:58 piaware systemd[1]: Stopping Lighttpd Daemon…
Feb 22 13:41:58 piaware systemd[1]: Stopped Lighttpd Daemon.
Feb 22 13:41:58 piaware systemd[1]: Starting Lighttpd Daemon…
Feb 22 13:41:58 piaware lighttpd[6360]: 2021-02-22 13:41:58: (plugin.c.187) Cannot load plugin mod_setenv more than once, please fix your config (lighttpd may not accept such configs in future releases)
Feb 22 13:41:58 piaware lighttpd[6360]: 2021-02-22 13:41:58: (server.c.1295) WARNING: unknown config-key: setenv.set-response-header (ignored)
Feb 22 13:41:58 piaware systemd[1]: Started Lighttpd Daemon.
Feb 22 13:41:58 piaware lighttpd[6369]: 2021-02-22 13:41:58: (plugin.c.187) Cannot load plugin mod_setenv more than once, please fix your config (lighttpd may not accept such configs in future releases)