New user, need help with the MLAT function


#1

Hello everybody,

I have recently assembled an ADS-B reciever with a raspberry pi 2 model B computer. I first started testing it yesterday with one of the first versions of Piaware (v1.2 I think). This morning I upgraded it to one of the latest versions (v2.1) which should include MLAT. On my stats page I enabled MLAT and it says that I am synchronized with 6 nearby recievers. I spent the whole day with my computer and my ADS-B on, I haven’t caught a single aircraft with MLAT yet (no purple planes at all). I have checked with flightradar 24 and there were aircraft flying near my location without ADS-B (only mode S transpoder), it said T-MLAT radar in their descriptions. My antenna is placed indoors (to poor for an outdoor antenna lol, still a student) and clearly recognizes ADS-B equiped aircraft within a 60/120 mile radius. Is this normal or I didn’t configure my software properly ?
Thanks in avance for your help :wink:

Regards Andre.


#2

hi andre,

there are different things that could went wrong e.g. the new piaware uses another port for mlat results (30104) than older versions of piaware and dump1090 use (30004) - see this thread http://discussions.flightaware.com/ads-b-flight-tracking-f21/piaware-2-1-3-released-t36047.html. you could look into your piaware log


cat /tmp/piaware.out

and post the result here.

what is your actual dump1090 version? there are older versions that won’t display mlat results.

another option - if you have a second sd-card - try the ‘plug and play solution’ sd-card image

have fun
tom

p.s. regarding your antenna you find very good tips from user abcd to improve reception without money: http://discussions.flightaware.com/ads-b-flight-tracking-f21/three-easy-diy-antennas-for-beginners-t20177.html


#3

Another thing is even though you are synchronized with 6 sites, 4 of them have to be seeing the same aircraft. So if you and 2 others see it, but the other four don’t see it, you won’t track it. I would probably suspect the flightaware servers though. They have been a little on the fritz lately.


#4

Good morning guys (if you’re in europe),

Thanks for the answers, after typing your code in my pi it was written that I had;
piaware version 2.1-3, process ID 1970, my system is a Linux piaware 3.18.5-v7, my program is listening ADS-B data on port 30005 (apparently the old version !), it’s reaching the server on 70.42.6.198/1200.

I honestly absolutely don’t know how to check my dump 1090 version, I guess it’s the old one. I will try to update all of these things but I am still waiting for a response from you if it doesn’t bother you. Your help is welcome. :wink:

Regards Andre.


#5

BTW (sorry for double post), regarding the post about DIY antennas, I have already seen it and was surprised about how simple it was to build one. I will maybe attempt to do this in the future but for now I will stick with my basic indoor antenna it’s good enough :slight_smile:


#6

andre,

if you have a second sd-card my recommendation still is to install the flightaware image. then you have a stable and common basis for further improvements. most things will work out of the box - and it is much less time consuming than tweaking here and there on an unknown installation.

regarding abcds antenna tips - if you have the small fixed standard antenna - just cutting off the top like shown brings improvements of about 20%

regards
tom


#7

Congrats Tom, you were right my dump 1090 was outdated, I updated EVERYTHING in my ADS-B stats page and I’ve started recieving several aircraft via MLAT. Thanks a lot I will read that post again, +20% seems very intersting. Thanks again.

Regards Andre.


#8

perfect :slight_smile: have a nice weekend


#9

p.s. this is abcds post about cutting top of standard antenna: http://discussions.flightaware.com/post181308.html#p181308