Question regarding MLAT numbers on my receiver

I have a question regarding my MLAT stats for two of my receivers. It seems during the peak times (daylight) MLAT numbers are low, but off peak times (evening) MLAT numbers skyrocket. Would anyone have a reason for this? Two of my receivers show this behavior, but one is the opposite scenario. … tats-33264 … tats-36800

And of course after I ask, the two previously mentioned receivers doubled in numbers today, while the previously high numbered​ receiver had its data cut in half.

Do synced receivers change that often where numbers would flucuate that much?

The mlat servers were rebalanced on Saturday which fixed load-related issues in busy areas (your two receivers that improved). The other receiver probably shifted regions during the rebalancing which affects which other receivers it will synchronize with.

Yeah I noticed one receiver was previously synced with over a hundred receivers now it’s only 30. Which is a bummer because it’s a 3,700 feet so coverage was awesome. Numbers went WAY down.

I’m curious about the underlying mechanics of this. ( Off the top, this isn’t a complaint at all, I’m just a relatively new entrant into this space and curious. :slight_smile: )

Doing a quick scan of the local piaware log, there doesn’t seem to be a significant change in the number of MLAT receivers synced with. Prior it looks like 75-85 , after more like 60-70. ( I can pull more accurate averages if that’s relevant. )

When I compare the number of MLAT positions reported vs the number of MLAT planes seen, the positions values starting 3/18 are about 50% for the same number of planes seen. Initially, I saw this thread and presumed that it was just the server rebalancing that was mentioned.

However, I also noticed another receiver about 40mi from me that had been offline for a while came back online on 3/17 as well, so I was very curious if there was a relationship between the two. I don’t recall if that effect existed before they were offline, as I was just getting started with this and playing with my setup a bit.

Just a small comparison snippet here, picked similar planes seen values.
(Date . MLAT planes / MLAT positions)

My site : 38758
3/13 . 1274 / 455,977
3/16 . 1275 / 417,098

3/22 . 1285 / 212,971
3/24 . 1253 / 199,321

Other site : 15876 (Offline until late day 3/17)
3/22 . 1361 / 516,657
3/24 . 1381 / 523,184

I know this isn’t apples to apples at all, but with two things changing at once, just got me curious. Wasn’t sure if another ‘busy’ station impacted MLAT in some way, or if this is just a function of the server balancing.

I’m also having some rather strange results since the rebalancing of the mlat servers. My local stats for ADSB Aircraft Seen/Tracked now show a large increase in the number of aircraft w/o positions and a large drop in the number of mlat aircraft. Aircraft w/o positions was the lowest on the chart before, but now mlat is at the bottom. This seems unusual as I’m currently showing “synchronized with 68 nearby receivers,” about the same as before.

I guess it is possible that I could have some other problem and it is just a coincidence that it happened at the same time the servers were rebalanced or there could be some other explanation.

I’m guessing that the MLAT servers were rebalanced again yesterday afternoon or some other adjustment was made.

My MLAT numbers are looking more normal now. They had dropped severely after the rebalancing in mid March. I see other stations are also showing an increase. It’s good to see things getting back to normal.

Yes, the regions were rebalanced again yesterday (the Ops fairy left me some new hardware)