[quote=“mighty3507”]
I installed Piaware 2.1-1 and Dump1090-mutability 1.15-dev late Friday local. Below are the graph of some early results. I have seen a ‘flip’ of my count of ‘with Positions’ vs ‘No Positions’ aircraft.
Before MLAT, ‘No Positions’ was the majority. After MLAT, ‘with Positions’ have become the majority. The spikes are caused by the periodic reception of TIS-B aircraft near KLAX.
/quote]
I have noticed a huge increase on my local stats as well. Still not showing on FlightAware.
I couldn’t wait any longer and changed to dump-mut 1.15-dev and piaware 2.1-1. At 11 PM my load average is consistently over 1. I’m hovering around 1.2. I’m already overclocked by one setting (800mhz?). I can’t image what daytime traffic will do. Messages/minute at night are what they typically are during peak daytime. I guess I’ll try a little higher overclock. I do have a Pi2 I can swap out.
Is there a way to add a timer like is used for the ADSB aircraft to remove the MLAT aircraft from the map when no position change has been received for x-seconds? I seem to be at the end of the line and I’ll see aircraft come toward me then stay in place til they are out of my range.
It’s a little tricky to work out exactly what to do there. Dump1090 hides aircraft when it has not seen messages from them at all for 60 secs. But for mlat aircraft it is common to stop receiving positions because it has moved out of mlat coverage (often when descending, receivers start losing contact) but you still hear the aircraft’s direct messages so it doesn’t expire. This is actually the same as adsb, you just notice it more often with mlat because you tend to lose both adsb messages and all other messages at about the same time.
Not sure if it’s related but after you made this change the next morning my Pi would hang when attempting to ssh into it, I reset it last night and it worked overnight and I was able to maintain an ssh connection to watch the load go up to 5.55 this morning (getting close to peak time for my area), I did an “ls” in one of the folders and my SSH session just hung, I can see it’s still outputting results to the web interface but it looks to have stopped pushing data to FA and I still can’t ssh into it.
Do you think excessive load would prevent SSH from establishing a connection as I am running dump1090 in “aggressive” mode combined with the MLAT overhead? or does it sound more like I’ve got a shagged SD card?
cheers izy
PS I’ve been running aggressive mode since installing the unit some 180 days ago and it’s never locked up like this before.
Thanks obj, I’ll reset it tonight and turn off aggressive and see how it goes, I’ve got 3 x Pi 2 B’s coming, 2 for the new feeder locations and I’ll use the other one to upgrade this existing Pi B+, I think the Pi B+ will do nicely with a GPS hat as an NTP server!
Do you have a recommended list of switches to use when running dump1090?
Hopefully a few more stations will come on line near me to keep them moving past me. I see the most toward my northwest as they travel between the Atlanta, Ga / Charlotte, NC area and most of them move til I stop receiving them. Thanks
I watched one of those last night. In the beginning, I only had direct messages from this plane. I presumed that I was coming in from the Atlantic and not enough other stations were receiving messages to provide an MLAT position. As it came nearer to the cost, MLAT positions started to come in and the plane appeared on the map. This continued for some time until MLAT coverage was lost again. However, I was still receiving direct messages for another few minutes. With the plane selected, it showed me an unchanging MLAT-derived position (i.e. last known position) together with a counter indicating the age of that position.
My suggestion here is that when the age of the last know position reaches 60 seconds, the plane is removed from the map but kept in the list until it does not receive any messages at all and then ages out in the normal way.
