MLAT Network


#1

Does the PiAware Network and the FlightFeeder Network work along to generte (calculate) MLAT?
Or are they each on there own?

There are 3 flightfeeder in my area and i want to know if adding a PiAware station will be enough so that MLAT can appear?
Or are the MLAT’s from Flightfeeder only for FlightFeeder and the PiAware’s MLAT only for Piaware?


#2

Flightfeeders don’t currently do mlat. When they do, they should share with all other mlat devices in FAs network(well those within range anyway).
4 devices would be better than 3. It couldn’t hurt to add another.


#3

I didnt know that Flightfeeders dont do MLAT.
when will they activate that option? The MLAT detection number already appears in my FlightAware status page.

OK, let’s refrase the question.

When FlightFeeder’s do MLAT, will they work with a PiAware?
There are 3 FlightFeeders’s working in my area and I’m planning to get a PiAware (3 FlightFeeder’s + 1 PiAware = 4 devices)


#4

Yes, when Flightfeeders get mlat (I don’t have a date for that yet, sorry) they will interoperate with piaware receivers.


#5

I believe that all four devices will work with mlat when the Flightfeeders support mlat.


#6

Thank you both for the answer’s…
I hope the MLAT option is turned on soon for the flightfeedre’s


#7

Hi Community,
I am a noob, operating PiAware (3.5.3) since 22 days now from a remote area in the Southern Central Pacific Ocean.
Locally another operator runs eight sites from airport terminals his airline serves. Distances are large – between 130 and 270NM from my location however his sites consistently get targets in the 200-250NM range due to high elevation placement of his antennas and completely clear airspace.
Therefore very often three or four of our combined feeders are observing the same targets simultaneously.
All his devices are FlightFeeder 7.9.1~bpo8+1 with MLAT supported/enabled.
However, when I look at my user stats, all nine of the feeders listed in the bottom table as nearby sites show a red cross in the MLAT column, regardless the green rectangle top left ‘MLAT’ with the ? in the circle when hovered over reports “synchronized”.
One observation I make is that his sites are accurate only to one or two decimal places of a degree LAT/LONG.
My position (self entered as are his) is accurate to five decimal places.
Could this be the reason the MLAT server is not able to syncronize our positions and thus create meaningful positions?
BTW there are definitely Mode-S targets in the area as I observed one on PiAware only this morning with the ICAO tag of 901008 but no position, height, speed etc data.
Any comments or advice on this would be greatfully received.
Thanks in advance.


#8

All the devices I enabled GPS PPS on have had higher MLAT results and seems to increase the observed aircraft marginally
by @mrzhi
Observations of results from different setups


#9

First, this thread is really really old. FlightFeeders and PiAware are on the same MLAT system. This has been true for long time.

MLAT is tricky without GPS timing:
With GPS timing you only need a plane to be seen by 4 receivers at once to get a MLAT lock

Without GPS timing you site needs to see an ADSB plane to get the timing information. Then you need to see a mode-S plane with 4 receivers at once to get a MLAT lock. Basically, you need to have multiple planes around to get the timing to do MLAT on a mode-S plane.


#10

GPS timing is also tricky. Just adding a USB GPS to a PiAware will not give you GPS timing. The GPS needs to talk to the receiver to get GPS timing.

GPS added to Raspberry pi not good for GPS timing
GPS added to Receiver is good for GPS timing


#11

Every week a new coverage map is made with last weeks data.
This is a current map of only last weeks data.

You can turn on the MLAT layer to see if your area has MLAT coverage.


#12

Only you can see your position accurate. We can’t see it on map, if you didn’t enable it. Others positions might be also shown truncated to the world, but MLAT has the whole info.
See the config on the web page of your feeder:

Position