Piaware: 234 aircraft, 1700/sec messages, map doesn't show jumbo flying over my house

FlightAware ADS-B Flight Tracking
1

Greetings,

My PiAware build is a few weeks old. It seems to work flawlessly, my ranking grows. I’m very close to IAD, very many planes. For the last week, it seems to have changed behavior. The map is sluggish viewed on my laptop on the LAN. While I see planes out to 250+ miles, >200 at a time, routinely the only thing I really care about doesn’t work, it won’t show a plane I clearly hear flying by. I just snapped the picture below as an example, right after it finally showed up on the map. Notice it says 1021 messages, so clearly it was tracking this plane probably even on the runway, but it only showed up about where you see it here.

image
image1112×753 292 KB

Here is htop running, resource usage is low:
image

Here are recent log messagesy:

Jan 26 17:20:59 ADSB piaware[464]: mlat-client(9424): Server: 1.1 kB/s from server 0.0kB/s TCP to server 2.1kB/s UDP to server
Jan 26 17:20:59 ADSB piaware[464]: mlat-client(9424): Results: 504.3 positions/minute
Jan 26 17:20:59 ADSB piaware[464]: mlat-client(9424): Aircraft: 74 of 130 Mode S, 64 of 81 ADS-B used
Jan 26 17:23:55 ADSB piaware[464]: 3754263 msgs recv’d from dump1090-fa (3592 in last 5m); 3701704 msgs sent to FlightAware
Jan 26 17:28:55 ADSB piaware[464]: 3757754 msgs recv’d from dump1090-fa (3491 in last 5m); 3705195 msgs sent to FlightAware
Jan 26 17:33:55 ADSB piaware[464]: 3761261 msgs recv’d from dump1090-fa (3507 in last 5m); 3708702 msgs sent to FlightAware
Jan 26 17:35:59 ADSB piaware[464]: mlat-client(9424): Receiver status: connected
Jan 26 17:35:59 ADSB piaware[464]: mlat-client(9424): Server status: synchronized with 283 nearby receivers
Jan 26 17:35:59 ADSB piaware[464]: mlat-client(9424): Receiver: 1812.0 msg/s received 191.8 msg/s processed (11%)
Jan 26 17:35:59 ADSB piaware[464]: mlat-client(9424): Server: 1.3 kB/s from server 0.0kB/s TCP to server 2.3kB/s UDP to server
Jan 26 17:35:59 ADSB piaware[464]: mlat-client(9424): Results: 586.1 positions/minute
Jan 26 17:35:59 ADSB piaware[464]: mlat-client(9424): Aircraft: 93 of 157 Mode S, 59 of 75 ADS-B used
Jan 26 17:38:55 ADSB piaware[464]: 3764714 msgs recv’d from dump1090-fa (3453 in last 5m); 3712155 msgs sent to FlightAware
Jan 26 17:43:55 ADSB piaware[464]: 3768173 msgs recv’d from dump1090-fa (3459 in last 5m); 3715614 msgs sent to FlightAware
Jan 26 17:48:55 ADSB piaware[464]: 3771565 msgs recv’d from dump1090-fa (3392 in last 5m); 3719006 msgs sent to FlightAware
Jan 26 17:51:00 ADSB piaware[464]: mlat-client(9424): Receiver status: connected
Jan 26 17:51:00 ADSB piaware[464]: mlat-client(9424): Server status: synchronized with 286 nearby receivers
Jan 26 17:51:00 ADSB piaware[464]: mlat-client(9424): Receiver: 1708.5 msg/s received 179.7 msg/s processed (11%)
Jan 26 17:51:00 ADSB piaware[464]: mlat-client(9424): Server: 1.4 kB/s from server 0.0kB/s TCP to server 2.1kB/s UDP to server
Jan 26 17:51:00 ADSB piaware[464]: mlat-client(9424): Results: 632.8 positions/minute
Jan 26 17:51:00 ADSB piaware[464]: mlat-client(9424): Aircraft: 70 of 145 Mode S, 58 of 84 ADS-B used
Jan 26 17:53:55 ADSB piaware[464]: 3775047 msgs recv’d from dump1090-fa (3482 in last 5m); 3722488 msgs sent to FlightAware
Jan 26 17:58:55 ADSB piaware[464]: 3778603 msgs recv’d from dump1090-fa (3556 in last 5m); 3726044 msgs sent to FlightAware
Jan 26 18:03:55 ADSB piaware[464]: 3782166 msgs recv’d from dump1090-fa (3563 in last 5m); 3729607 msgs sent to FlightAware
Jan 26 18:06:00 ADSB piaware[464]: mlat-client(9424): Receiver status: connected
Jan 26 18:06:00 ADSB piaware[464]: mlat-client(9424): Server status: synchronized with 302 nearby receivers
Jan 26 18:06:00 ADSB piaware[464]: mlat-client(9424): Receiver: 1815.1 msg/s received 186.8 msg/s processed (10%)
Jan 26 18:06:00 ADSB piaware[464]: mlat-client(9424): Server: 1.2 kB/s from server 0.0kB/s TCP to server 2.2kB/s UDP to server
Jan 26 18:06:00 ADSB piaware[464]: mlat-client(9424): Results: 563.4 positions/minute
Jan 26 18:06:00 ADSB piaware[464]: mlat-client(9424): Aircraft: 76 of 135 Mode S, 68 of 84 ADS-B used
Jan 26 18:08:55 ADSB piaware[464]: 3785703 msgs recv’d from dump1090-fa (3537 in last 5m); 3733144 msgs sent to FlightAware
Jan 26 18:13:55 ADSB piaware[464]: 3789249 msgs recv’d from dump1090-fa (3546 in last 5m); 3736690 msgs sent to FlightAware

Any idea why it’s having issues displaying my aircraft when it seems to be working so well?

Thanks,
–Scott

2

If the signal is too strong it will overwhelm the receiver. The closer the plane is to you, typically the stronger the signal will be. Also, some transmitters are more powerful than others. reducing the gain lets you track close in aircraft at the expense of tracking distant ones.

3

-1.6dBFS is a really strong signal(as stated above). Anything above -3 is considered very strong. It’s like trying to listen to someone talking to you at a rock concert. Not easy.

1700 msg/sec is also really high. My radarcape can barely cope with that.

4

Thanks for the ideas guys, maybe that’s it. The gain is set to “auto” though, although I have no idea how that is implemented. You would think it would figure out that planes constantly fly over my house and set the gain accordingly, which might hurt my distance reception. So, is there a way to monitor the performance of the SDR? That is, how can I see what the parity or other error rates might look like to debug this? I tried searching but find nothing.

5

With Auto you mean AGC via setting -10? That leads to a gain a little above 50, which is even higher than the highest manual gain you set manually.

The automatic gain works with a constant signal like TV, but not with the many different and short adsb messages.

To find the „best“ gain value, you can use a python script. Just search this forum for posts by @abcd567, or @obj, who maintains dump1090fa and knows a thing or two about it.

1 Like
6

Regarding distance, you could you use virtual radar server and use the range map feature. Or look for a adsb receiver project, it offers a way to collect stats.

The is a wealth of information about this on this forum, sadly it is not so visible and accessible on the now not-so-new-anymore version of the forum

7

@sbierly
@biekerc

.
TWEAK-3: Gain Optimization Scripts

1 Like