Fake results?


#1

I am puzzled by the results that a receiver site located close of me gets. It manages to pull more than double of the positions that anyone around him pulls.
Is this for real or it is somehow faked (like he combines two sites in one)?



#2

What is your set up and is your antenna mounted outdoors?


#3

Look at his range stats.
He doesn’t have as much close in traffic as you. This could allow him to run a higher gain setting and/or see more position reports

He could also be feeding his piaware with a radarcape or other sensitive/fpga receiver.
I get over twice the position reports compared to my neighbours. Often I am not the top aircraft receiver as others are in better locations(I am blocked for over 120 degrees to the south/east)


#4

My antenna is outdoors, above roof line. I don’t know about other’s antennas, but I assume they are also outside, since some have better numbers. Anyway, none is getting even 1/2 of the numbers from the station I ask.
And if you look, it seems that the bulk of his numbers are fairly close-by, 100-150 miles.
I don’t think he can run more gain, if I add more gain, the clipped signals go trough the roof (two near-by airports and heavy air traffic lanes above) and the far-away planes just disappear.


#5

As above, they could have a better Rx than you and the gain optimised for the area.


#6

You will get more clipped signals, drowning the far-away ones. Tried it already.


#7

Compare his graphs to yours. You have a lot more close in than he does.


#8

I was meaning the other way… I increased my messages about 30% by reducing the gain after running the test script elsewhere on these pages. using a FA Antenna/Pro Stick +.


#9

Yes, I see that.
It cannot be higher gain (preamp or antenna), because the close-by signals will overload the receiver, as I already said. You can’t “filter” those stronger signals (local) out.
If he had a higher antenna, it would pick up at least the same amount of close-up signals.

But if he has another receiver, at some 120 miles away, and it is adding those signals somehow with the one close-by, then the pattern would be explained clearly.

So, like I said, it puzzles me. What else can it be?


#10

Not saying you can do anything.
He is just in a location that works better or has better equipment.


#11

I also notice that most of his signals are coming from his “NNW” sector. Like it is indeed another receiver located there.

This is because the air traffic here goes NNE-SW, from NY/DC area to Florida and South America. You can see it on my heat map.

But his looks like this:


#12

Have a look at the report for say 2AM this morning.
You get 1500 position reports and 28 aircraft
He gets 5200 position reports and 73 aircraft.

The circle on the map looks to be around Washington D.C.
His receiver my just have a better line of sight to the D.C. airports


#13

There is no line of sight from where we are with the planes landing in Washington DC airports, they are too “low”.
Not unless he has a receiver on the ground there, piping the data to the receiver here in SE VA.

PS: I can see also some planes there (Wash DC, Dover, even Baltimore), but only if they are at 30-40k feet high. See the pic below, the small plane in top-left was a Dassault Falcon 900EX at 43k feet.


#14

Whilst I did say D.C. Airports, I meant NAV aids and high level routes near them.


#15

i’d guess site 59126 is more than only one receiver/antenna because he has a too low proportion of mlat to adsb/other compared to other feeders in his area. in addition isn’t synced to any other mlat stations …

https://flightaware.com/adsb/stats/user/Surveillance911


#16

That’s right, thanks for noticing that!
I guess it will be able to MLAT only from the local results, but not for the ones that are piped in from far away (obvious timing issues).


#17

My radarcape has MLAT with only 10% the total position reports.
He does get MLAT, it just isn’t working at this moment.
It dropped off in the last hour.

(I am not saying that it is not possible it is being fed with multiple sites. I am just saying that it is possible that he is not).


#18

If that’s the local situation around you (not enough stations around you), then is probably fine.
But all the stations around us have multiple MLAT partners. I am synchronized with 121 nearby receivers.


#19

the mlat proportion highly depends on the area - and in your area the low rate is quite common - but not in his.


#20

His MLAT is back. Synced with 115 other devices.