Upgrade to Bookworm = fewer tracked aircraft

[jnyc]

I recently upgraded a very old installation of piaware, from Sketch (around 2018-9) to Bookworm. I retained the same dump/piaware settings across the upgrade and now I am seeing around 2-300 fewer aircraft a day. I’m running the latest piaware on a Pi 3B+, the same hardware as before including antenna and Flightaware Pro Stick Plus (the blue one). Anyone seen anything similar?

[MC130E]

@jnyc

I recently upgraded a very old installation of piaware, from Sketch (around 2018-9) to Bookworm. I retained the same dump/piaware settings across the upgrade and now I am seeing around 2-300 fewer aircraft a day.

Hi,

One setting to check.

You mentioned that you are using the same settings as before, but make sure you check for something called Adaptive Gain. If you had done an upgrade in place, the new feature would have been disabled by default. It would be using your manual gain setting exactly as before.

However, since you upgraded from such an old version, you probably did a fresh install and then copied over your old settings. This fresh install would have adaptive gain enabled by default. Your manual gain would be used as the starting point, and then it would occasionally hunt up/down for what gain value it thinks is best. A good manual gain is often better.

You can read about the feature in the release post below. The first paragraph has a good summary.

Announcing the release of PiAware 6

Today we’re excited to announce the release of PiAware 6! This version includes a new adaptive gain feature, updates to the PiAware LCD image, performance improvements for Raspberry Pi’s with slower CPUs, and more. Read the full release notes below: Adaptive Gain: Adjusts receiver gain automatically to find a reasonable gain setting for the local RF environment. Adaptive gain is enabled by default on new installations only. For existing systems that are upgraded from an older version to 6…

Full details and how to disable it are at the Github link below: (link from post above)

README.adaptive-gain.md

I use the FA package installs like you do. I have adaptive gain disabled in /etc/default/dump1090-fa as below:

Adjust gain to try to achieve optimal dynamic range / noise floor?

ADAPTIVE_DYNAMIC_RANGE=no

Regards,
-Dan

[jnyc]

Thanks for the detailed information!

I doubled checked my configuration and it is the same as it was on my very old piaware install on Sketch. I’m wondering if it’s the Pi drivers for the RTL side of things that have changed, seems reasonable considering the age of Sketch! I will continue to tinker in the mean time. Thanks again!

[jonhawkes2030]

It is possible that the later code removes junk messages better. This could lower your aircraft count.

[jafrank]

In the interest of clarity for others that might follow, I am pretty sure that your old version was “Stretch”, rather than “Sketch”.

Debian versions are named after characters from the Toy Story movies. Stretch was a purple rubber octopus in Toy Story 3.

[jnyc]

One thing I failed to mention is that my original piaware setup was running a piaware image downloaded from Flightaware. The upgraded pi was a standard build of Bookworm with piaware installed as a package. So now I am wondering whether the original piaware image had some additional optimisations?

I’ve been experimenting for two weeks now with different gain settings, burst enabled not enabled, various baseline gain settings and dynamic ranges and I still can’t get back to my usual 1600+ aircraft a day, the closest I’ve got so far is 1300+.

Has anyone else experienced the same?