I don’t know if someone already asked about filtering VIP aircraft’s. Today I did not see any mlat positions of the Air Force One here in Germany. I registered about 14000 Mode S signals in 30 minutes and saw the AF1 above my head.
Is there something filtered?
I asked the same question here. When the president visited Austin recently I could not get an MLAT fix & another local user also reported no MLAT on AF1 that day.
However, other users have received MLAT on the same aircraft many other times. So I have no idea why sometimes it seems un-mlat-able!
Alaska has six times as many pilots per capita and 16 times as many aircraft per capita when compared to the rest of the United States. (1 in 400 vs 1 in 60 pilots per capita) It’s lower in the city of Anchorage and higher in the smaller towns and villages, some are 1 in 10. If they’re not registered it makes it hard to count them! Transponder-less, absolutely we have many that use 978 UAT only.
Float planes?, I have no idea, but we have many just here at Lake Hood where I park, over 780 aircraft total. Merrill Field in town has over 844 aircraft and only 91 aircraft based at the very busy Ted Stevens International airport. I would say it’s more important where aircraft are based or operated than where they’re registered.
More statistics here: aircraftone.com/aircraft/reg … pcodes.asp
Can a PiAware sync with a MLAT enabled Flightfeeder ?
Yes
Disable --Mode-AC
in dump1090-mutability (/etc/default/)
Reboot dump, that did the magic here…
From 42% CPU to 29-32%
Than i enable mlat, still 32%
Try it…
(# Additional options that are passed to the Daemon.
EXTRA_ARGS=“–metric --net --net-http-port 8080”)
RPi B+ 600MHz (under clocked)
88.159.160.147:8080
On my stats page:
flightaware.com/adsb/stats/user/HenryAbbott
I see three sites. Only the middle one shows m-lat as active. Is there some option that must be activated or selected for the other two sites to also show m-lat as active? Or does it simply mean that other two sites never see any m-lat signals. This is important, as we are mainly interested in seeing small aircraft.
If it is some setting or option that I must activate, please give details.
It might also be that my lat-long info is not accurate. Where do I reset this?
If it is a lack of stations I might just try and get some F24 guys to contribute to FA as well or see if I can get another interested soul with 24h internet connection.
Looking forward to your comments!
Henry
The other sites support it, there’s just not enough coverage in your area – we need more PIAware and FlightFeeders to really do MLAT well in your area.
For MLAT to work, we need at least 4 receiver sites (preferably more) receiving the same signal from a given aircraft at the same time. Additionally, each site must have MLAT-capable PiAware (or FlightFeeder) software running on it. With only 3 sites total in your area, we do not have enough coverage to do MLAT. When enough sites are available, MLAT calculations will start automatically.
On the map it looks like a sparsely populated area, the present three receivers are spread over 100 miles
The receivers for MLAT need to more or less surround the planes and must all receive mode S signals from the planes - with the 100 miles spread, they will all only see high altitude planes.
To see the low ones, you would need a receiver spacing of 5 - 30km and the four (or more) receivers.
PiAware raspberry pi based receivers would do the job, but getting hold of the bits to put them together can be torturous and expensive in SA … then you need Internet availability to connect them up.
Could the planes be equipped with Flarm ( en.wikipedia.org/wiki/FLARM ) - this can work like a much lower cost ADSB with the planes transmitting thier location, so you’d just need a local reciever.
I’m the Seattle area and have lots of MLAT syncs:
Feeder Type: PiAware (SD Card) 3.1.0
Multilateration (MLAT): Supported / Enabled (synchronized with 47 nearby receivers)
but I’m not seeing MLAT aircraft on the piaware:8080 map. This is in spite of seeing MLAT tracks (with lat/lon) for the missing aircraft (based on ICAO) looking at the output from port 12345 directly on the PI itself.
I haven’t changed anything on my end. Has anything changed with the HTML rendering engine for the piaware:8080 page? ADS-B flights still shows up fine.
Thanks,
David
Uh, the piaware sdcard image does not produce output on port 12345. Are you running a modified image?
Obj is right. Mlat is on port 30105.
No, not running any kind of custom bits.
Going through post history I do now remember that I added an extra port for MLAT output:
However this never caused a problem with my piaware:8080 display before, but I guess now it does. A regression maybe?
David
Maybe you have turned off the original connection for mlat results by mistake, then they would not get fed back into dump.
In Piaware 3 the syntax for mlat-results also changed, so the old syntax for changing the setting will not work any more.
ads-b-flight-tracking-f21/mlat-data-into-vrs-separate-feed-t38230-25.html?hilit=mlatresults
/M
I haven’t made any configuration changes in a year since the post I quoted earlier.
In the past year since I made the configuration change piaware:8080 has been working fine, until just recently.
I know very well that running with anything but the default configuration is not officially supported, and I guess recent some code change somehow broke it. I do hope there is still a way to independently collect the MLAT data without breaking the piaware:8080 display.
The ability to access the MLAT data you help create is the main benefit of feeding to FlightAware instead of FlightRadar24 and is why I exclusively feed to FlightAware. I hope that’s still possible.
Thanks,
David
Something obviously changed. Did you let FA auto-upgrade piaware or not?
Check the current operating settings, Is there any connection between fa-mlat and dump on 30104, or not?
Just repeating “I didn’t change anything” isn’t going to help. There is nothing wrong with mlat-results in the new version, but, again
/M
Well, if it’s nothing immediately obvious, then you need to provide enough information to actually diagnose the problem: your piaware and dump1090 versions, your actual configuration (output of “piaware-config”), contents of /var/log/piaware.log. Without that info, I’d just be guessing.
Thanks for taking a mental interrupt to think about this at all; I understand that since I did make a change to the configuration to add an MLAT output port I’m likely the only one experiencing this problem.
I have “Auto-update PiAware software” enabled so in theory should be running the latest and greatest. According to ‘My ADS-B’ I have “PiAware (SD Card) 3.1.0”. I’m not actually going to be able to RemoteDesktop into the Pi until this coming weekend to gather more version and other details/logs.
I was planning to just flatten and rebuild the Pi with a new PiAware image, verify everything works, and then use the new command to add an addition MLAT output port. However if you guys are interested for your own reasons in understanding why my config change is interoperating with the new bits this way, I’m more than happy to provide whatever details/logs are needed to debug.
Let me know, and thanks again for the help.
David
If you can provide the things I asked for above when you have a chance then I’m happy to take a look.